RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: A computer store offers employees a 20% discount off the retail price. If the store purchased a computer from the manufacturer for $1000 dollars and marked up the price 20% to the final retail price, how much would an employee save if he purchased the computer at the employee discount (20% off retail price) as opposed to the final retail price.
A.$1,000
B.$960
C.$240
D.$200
Answer: C.$240
Explanation: Cost price=1000
Profit=20% =20% of 1000=200
selling price=CP+ Profit
SP=1200
a Discount of 20% to employees means 20% off on 1200
so 20% of 1200= 240
so a employee thinks he saved 240..
Answer: C
Question: A cycle is bought for Rs.900 and sold for Rs.1080, find the gain percent?
A.28%
B.20%
C.80%
D.70%
Answer: B.20%
Explanation: 900 ---- 180
100 ---- ? => 20%
Answer: B
Question: If two times A is equal to three times of B and also equal to four times of C, then A:B:C is
A.2:3:4
B.3:4:2
C.4:6:3
D.6:4:3
Answer: D.6:4:3
Explanation: Solution: 2A = 3B;
Or, B = (2/3)A; And, 2A = 4C;
Or, C = (1/2)A;
Hence, A:B:C = A:2A/3:A/2 = 1:2/3:1/2 = 6:4:3
Answer: Option D
Question: if p/q=3/4
then3p+5q=?
A.25/4
B.29/4
C.20/4
D.35/4
Answer: B.29/4
Explanation: 3p+5q=?
Divided by q,
3(p/q)+5=x
3*(3/4)+5=29/4
ANSWER:B
Question: Harkamal purchased 9kg of grapes at the rate of 70 per kg and 9 kg of mangoes at the rate of 55 per kg. How much amount did he pay to the shopkeeper?
A.A)1120
B.B)1065
C.C)1070
D.D)1075
Answer: A.A)1120
Explanation: Cost of 9 kg grapes = 70 × 9 = 630.
Cost of 9 kg of mangoes = 55 × 9 = 490.
Total cost he has to pay = 630 + 490 = 1120
A
Question: A man can row at 5 kmph in still water. If the velocity of current is 1 kmph and it takes him 1 hour to row to a place and come back, how far is the place?
A.3.2 km
B.3 km
C.2.4 km
D.3.6 km
Answer: C.2.4 km
Explanation: Explanation :
Speed in still water = 5 kmph
Speed of the current = 1 kmph
Speed downstream = (5+1) = 6 kmph
Speed upstream = (5-1) = 4 kmph
Let the requited distance be x km
Total time taken = 1 hour
=> x/6 + x/4 = 1
=> 2x + 3x = 12
=> 5x = 12
=> x = 2.4 km. Answer : Option C
Question: If the given two numbers are respectively 8% and 16% of a third number, then what percentage is the first of the second ?
A.20%
B.25%
C.18%
D.50%
Answer: D.50%
Explanation: Here, l = 8 and m = 16
Therefore, first number = l/m x 100% of second number = 8/16 x 100% of second number = 50% of second number
ANSWER:D
Question: After decreasing 24% in the price of an article costs Rs.912. Find the actual cost of an article?
A.226
B.255
C.1200
D.2771
Answer: C.1200
Explanation: CP* (76/100) = 912
CP= 12 * 100 => CP = 1200
Answer:C
Question: A small company employs 3 men and 5 women. If a team of 4 employees is to be randomly selected to organize the company retreat, what is the probability E that the team will have exactly 2 women?
A.1/14
B.1/7
C.2/7
D.3/7
Answer: D.3/7
Explanation: 5C2 * 3C2 -> it gives combination of exactly 2 women and 2 men.
8C4 -> gives total possibilities of 4 people from 5 women and 3 men.
Probability = 5C2*3C2 / 8C4 = 3/7
SECOND METHOD:
Probability of two women -> 5/8 * 4/7.
probability of two men -> 3/6 * 2/5.
Probability: (5/8 * 4/7) * (3/6 * 2/5) = 1/14.
Question: Two trains, each 100 m long, moving in opposite directions, cross other in 8 sec. If one is moving twice as fast the other, then the speed of the faster train is?
A.110 km/hr
B.80 km/hr
C.60 km/hr
D.50 km/hr
Answer: C.60 km/hr
Explanation: Answer: Option C
Let the speed of the slower train be x m/sec.
Then, speed of the train = 2x m/sec.
Relative speed = ( x + 2x) = 3x m/sec.
(100 + 100)/8 = 3x => x = 25/3.
So, speed of the faster train = 50/3 = 50/3 * 18/5 = 60 km/hr.
Question: An urn contains 10 balls, numbered from 1 to 10. If 2 balls are selected at random with replacement from the urn, what is the probability B that the sum of the 2 numbers on the balls will be even?
A.25%
B.37.5%
C.50%
D.62.5%
Answer: C.50%
Explanation: Correct Answer: C
Since there are 5 even numbered balls and 5 odd numbered balls, the probability B of selecting either an even or an odd is 5/10= 1/2. In order for the sum of the numbers on the two balls to be even, either both numbers must be even or both numbers must be odd; one even and one odd number would add to an odd number. The probability of selecting two even numbers is:
1/2 * 1/2= 1/4
The probability of selecting two odd numbers is also:
1/2 * 1/2= 1/4
Adding both probabilities gives 1/4+1/4= 1/2 , or 50%, as the probability that the sum of the numbers will be even. Thus, the correct answer is (C).
Question: What is the rate percent when the simple interest on Rs.900 amount to Rs.160 in 4 Years?
A.4.44
B.5.44
C.6.44
D.7.44
Answer: A.4.44
Explanation: 160 = (900*4*R)/100
R = 4.44%
Answer: A
Question: When a number is divided by 4 &then multiply by 12 the answer is 9 what is the no.?
A.3
B.5
C.5.6
D.5.7
Answer: A.3
Explanation: if $x$ is the number, x/4 * 12 = 9
=> 3x = 9
=> x = 3
A
Question: A person bought an article and sold it at a loss of 10%. If he had bought it for 20% less and sold it for Rs.75 less, he could have gained 25%. What is the cost price?
A.250
B.276
C.976
D.267
Answer: A.250
Explanation: CP1 = 100 SP1 = 90
CP2 = 80 SP2 = 80 * (140/100) = 112
22 ----- 100
55 ----- ? => Rs.250
Answer:A
Question: A person's present age is two-fifth of the age of his mother. After 8 years, he will be one-half of the age of his mother. How old id the mother at present?
A.46
B.49
C.40
D.21
Answer: C.40
Explanation: Let the mother's present age be x years. Then, the person's present age = 2/5 x years.
(2/5 x + 8) = 1/2 (x + 8)
2(2x + 40) = 5(x + 8) => x = 40
Answer:C
Question: Speed of a boat in standing water is 14 kmph and the speed of the stream is 1.2 kmph. A man rows to a place at a distance of 4864 km and comes back to the starting point. The total time taken by him is:
A.700
B.200
C.540
D.120
Answer: A.700
Explanation: Explanation:
Speed downstream =(14+1.2)=15.2 kmph
Speed upstream =(14-1.2)=12.8 kmph
Total time taken=4864/15.2+4864/12.8=320+380=700 hours.
Answer:A
Question: At 1:00, Annie starts to bicycle along a 87 mile road at a constant speed of 15 miles per hour. Thirty minutes earlier, Scott started bicycling towards Annie on the same road at a constant speed of 12 miles per hour. At what time will they meet?
A.2:30
B.3:00
C.4:00
D.6:00
Answer: C.4:00
Explanation: In the first 30 minutes, Scott can travel 6 miles, so there are 81 miles left.
Together Annie and Scott can complete 27 miles.
81/27 = 3, so they will meet 3 hours after 1:00.
The answer is C.
Question: A certain sum of money is invested for one year at a certain rate of simple interest. If the rate of interest is 3% higher, then the invest earned will be 25% more than the interest earned earlier. What is the earlier rate of interest?
A.16
B.18
C.28
D.12
Answer: D.12
Explanation: If the interest earned is 25% more than the earlier interest then the rate of interest also should be 25% higher than the earlier rate.
Let the earlier rate of interest be x%.
Now it will be (x + 3)%
% increase = (x + 3) - x/x * 100
= 25
=> x = 12
Answer: D
Question: A person travels from P to Q a speed of 40 km/hr and returns by increasing his speed by 50%. What is his average speed for both the trips?
A.27
B.87
C.48
D.77
Answer: C.48
Explanation: Speed on return trip = 150% of 40 = 60 km/hr.
Average speed = (2 * 40 * 60)/(40 + 60) = 48 km/hr.
Answer: C
Question: There are four different models that are to appear in a fashion show. Two are from Europe, two are from South America, and two are from North America. If all the models from the same continent are to stand next to each other, how many ways can the fashion show organizer arrange the models?
A.192
B.48
C.64
D.24
Answer: A.192
Explanation: Since we have 3 continental pairs (EU, SA, NA), these 3 pairs have 4*3*2*1 = 24 Combinations. Within each pair, you have however 2 different ways to put them together for each of the pair (2*2*2 = 8). So we have 24*8 = 192.
Please correct me if im wrong.
Answer A.
Question: 30 men can do a work in 40 days. When should 16 men leave the work so that the entire work is completed in 40 days after they leave the work?
A.87 days
B.14 days
C.55 days
D.44 days
Answer: B.14 days
Explanation: Total work to be done = 30 * 40 = 1200
Let 16 men leave the work after 'P' days, so that the remaining work is completed in 40 days after they leave the work.
40P + (16 * 40) = 1200
40P = 560 => P = 14 days
Answer:B
Question: 14 men can complete a piece of work in 30 days. In how many days can 24 men complete that piece of work?
A.17 1/2 days
B.26 3/4 days
C.22 1/2 days
D.29 days
Answer: A.17 1/2 days
Explanation: A
17 1/2 days
14 * 30 = 25 * x => x = 17 1/2 days
Question: The radius of a circular wheel is 1.75 m, how many revolutions will it make in traveling 1 km?
A.1000
B.2788
C.2677
D.2899
Answer: A.1000
Explanation: 2 * 22/7 * 1.75 * x = 11000
x = 1000
Answer: A
Question: A manufacturer produces a certain men's athletic shoe in integer sizes from 8 to 17. For this particular shoe, each unit increase in size corresponds to a 1/4-inch increase in the length of the shoe. If the largest size of this shoe is 30% longer than the smallest size, how long, in inches, is the shoe in size 15?
A.9.25
B.11.75
C.13.25
D.15.75
Answer: A.9.25
Explanation: Let x be the length of the size 8 shoe.
Then 0.3x = 9/4
x = 90/12 = 15/2 inches
The size 15 shoe has a length of 15/2 + 7/4 = 37/4 = 9.25 inches
The answer is A.
Question: Joe is painting a rectangular room whose dimensions are given by a, b and c meters. Joe takes 4 hours to paint a wall with dimensions a and c. He takes 2 hours to paint a wall with dimensions b and c and 6 hours to paint the ceiling with dimensions a and b. If Joe works at a constant rate and a = 3, then what is the volume of the room?
A.4.5 cubic meters
B.2.4 cubic meters
C.3.0 cubic meters
D.3.6 cubic meters
Answer: A.4.5 cubic meters
Explanation: Time to paint each wall as given in problem:
AC = 4 hours
BC = 2 hours
AB = 6 hours
Since he works at constant rate and it takes him twice as long to paint AC compared to BC
AC=2BC
Plug in 6 for A and you find that B=1.5 Since painting AB takes 3 times as long compared to BC,
AB=3BC
Plug in 6 for A and 3 for B and you find that C=1
A*B*C=3*1.5*1=4.5 cubic meters
Answer: A
Question: If ABC us a three digit number such that no one number is similar to other than how many possible values of ( a + 4b + c ) will be divisible by 40 :
A.18
B.16
C.15
D.12
Answer: C.15
Explanation: a b c
4 9 0 *1 because if 0 comes in first it is not a three digit number
1 9 3 *2
1 8 7 *2
2 8 6 *2
3 8 5 *2
3 7 9 *2
4 7 8 *2
7 6 9 *2
15
ANSWER:C
Question: The sector of a circle has radius of 24 cm and central angle 135o. Find its perimeter?
A.91.5 cm
B.11.5 cm
C.104.6 cm
D.92.5 cm
Answer: C.104.6 cm
Explanation: Perimeter of the sector = length of the arc + 2(radius)
= (135/360 * 2 * 22/7 * 24) + 2(24)
= 56.6 + 48
= 104.6 cm
Answer:C
Question: Find the HCF of
23,46,827
A.227
B.83
C.23
D.827
Answer: A.227
Explanation: Answer: Option A
Explanation:
Whenever we have to solve this sort of question, remember the formula.
HCF =
HCF of Numerators LCM of Denominators
So answers will be option 1
Answer: Option A
Question: A certain school principal must choose 6 students to attend a field trip out of a group of 10 students. In addition, out of the 6 chosen students, the principal must select a note-taker and a treasurer. How many different ways are there for the principal to select the 6 students and then select the treasurer and the note-taker?
A.1,260
B.2,520
C.5,040
D.6,300
Answer: D.6,300
Explanation: 5 students can be selected out of 10 students in 10C6 ways.
out of the remaining 6 students,Note taker can be chosen in 6 ways.
Finally only 5 students remain from which we can choose a treasurer in 5 ways.
Total number of ways = 210 * 6 *5 = 6300
correct answer - D
Question: City A to city B, Andrew drove for 1hr at 42 mph and for 3 hours at 60 mph. What was the average speed for the whole trip?
A.55.5
B.57.5
C.61
D.61.5
Answer: A.55.5
Explanation: The total distance is 1×42+3×60=222
And the total time is 4 hours. Hence,
Average Speed=(Total Distance/Total Time)
=222/4=55.5
A
Question: A password of a computer consists of five digits 1 through 6. What is the probability that all digits are divisible by 3 ?
A.1/3
B.1/6
C.1/27
D.1/243
Answer: D.1/243
Explanation: For each digit there are six possibilities. Two of them (3 and 6) are divisible by three, so there is a one in three chance for each digit, and since the digits are independent of each other, overall probability is 1 / 3^5 or D
Question: 2/x + 3x = 3(x+2)
A.-9
B.1/3
C.-1/9
D.1/9
Answer: B.1/3
Explanation: We can solve - expand the right side, multiply by x on both sides and then subtract away the 3x^2 terms:
(2/X) + 3x = 3(x+2)
(2/x) + 3x = 3x + 6
2 + 3x^2 = 3x^2 + 6x
2 = 6x
1/3 = x
and to confirm, you can plug that answer back into the original equation to see that it makes the left and right sides equal.
B
Question: The average age of a class of 32 students is 16 yrs. if the teacher's age is also included, the average increases by one year. Find the age of the teacher
A.29 Years
B.32 Years
C.37 Years
D.49 Years
Answer: D.49 Years
Explanation: Total age of students is 32X16 = 512 Years
Total age inclusive of teacher = 33X (16+1) = 561
So, Teacher's age is 561-512 = 49 Yrs
There is a shortcut for these type of problems
Teacher's age is 16+(33X1) = 49 Years
D
Question: A bag contains 10 wool scarves, exactly one of which is red and exactly one of which is green. If Deborah reaches in and draws three scarves, simultaneously and at random, what is the probability that she selects the red scarf but not the green scarf?
A.3/11
B.5/23
C.7/30
D.9/37
Answer: C.7/30
Explanation: Total possible ways to choose three scarves is 10C3 = 120
We need to choose the red scarf and two of 8 other scarves (not the green scarf).
The number of successful possibilities is 8C2 = 28
P(red scarf but not green scarf) = 28/120 = 7/30
The answer is C.
Question: The water level in a rectangular swimming pool measuring 60 feet by 20 feet is to be lowered by 6 inches. How many gallons of water must be removed? (1 cu ft = 7.5 gallons)
A.100
B.250
C.4500
D.1200
Answer: C.4500
Explanation: 6 inches = 1/2 feet (there are 12 inches in a foot.), so 60*20*1/2=600 feet^3 of water must be removed, which equals to 600*7.5=4500 gallons.
Answer: C.
Question: On dividing a certain number by 342, we get 47 as remainder. if same number is divided by 18 . what will be the remainder?
A.7*9k+86
B.7*9k+56
C.8*4k+56
D.18*19K+47
Answer: D.18*19K+47
Explanation: number =324k+47
=(18*19k)+(18*2)+11
= 18*(19k+2)+11
= 18*19K+47
Answer(D)
Question: What is the probability that Carol and Bernie will get selected for a job they both applied for in a company, given that their chances of getting selected is 4/5 and 3/5 respectively?
A.8/25
B.11/24
C.12/25
D.12/25
Answer: D.12/25
Explanation: Explanation:
P(Carol) = 4/5
P(Bernie) = 3/5
E = {Carol and Bernie both get selected}
P(E) = P(Carol)*P(Bernie)
= 4/5 * 3/5
= 12/25
ANSWER: D
Question: A train which has 390 m long, is running 45 kmph. In what time will it cross a person moving at 9 kmph in same direction ?
A.26 sec
B.39 sec
C.36 sec
D.29 sec
Answer: B.39 sec
Explanation: Time taken to cross a moving person = length of train/ relative speed
Time taken = 390/((45-9) (5/18) = 390/ 36*(5/18) = 390/10 = 39 sec
Answer: B
Question: one gear of pulley rotates at a speed of 3 rev/sec another gear roates at 5 rev/sec. if both start together after how many seconds will they be together again
A.3 sec
B.5sec
C.15 sec
D.20 sec
Answer: C.15 sec
Explanation: 3 rotates 3,6,9,12,15
5 rotates 5,10,15
ans is 15
ANSWER:C
Question: A metallic sheet is of rectangular shape with dimensions 48 m x 36 m. From each of its corners, a square is cut off so as to make an open box. If the length of the square is 7 m, the volume of the box (in m3) is:
A.4830
B.5236
C.6420
D.8960
Answer: B.5236
Explanation: Clearly, l = (48 - 14)m = 34 m,
b = (36 -14)m = 22 m,
h = 8 m.
Volume of the box = (34 x 22 x 7) m3 = 5236 m3. Answer: Option B
Question: A train running at the speed of 90 km/hr crosses a pole in 6 seconds. What is the length of the train?
A.255
B.205
C.502
D.225
Answer: D.225
Explanation: Speed=(90 * 5/18) m/sec = (25) m/sec Length of the train = (Speed x Time) = (25 * 9) m
= 225 m.
Answer: D
Question: A train 180 m long is running with a speed of 55 km/hr. In what time will it pass a man who is running at 7km/hr in the direction opposite to that in which the train is going?
A.5.5
B.10.45
C.7
D.8
Answer: B.10.45
Explanation: Speed of train relative to man = 55+ 7 = 62 km/hr.
= 62 * 5/18 = 155/9 m/sec.
Time taken to pass the men = 180 *9/155 = 10.45 sec.
Answer: Option B
Question: The greatest number by which the product of three consecutive multiples of 2 is always
A.54
B.48
C.162
D.243
Answer: B.48
Explanation: Explanation:
2*4*6 = 48
Option B
Question: Danny and Steve are running towards each other, each one from his own house. Danny can reach Steve's house in 25 minutes of running, which is half the time it takes Steve to reach Danny's house. If the two started to run at the same time, how much time longer will it take Steve to reach the halfway point between their houses than Danny to reach the halfway point between their houses?
A.12.5 minutes.
B.25 minutes
C.35 minutes.
D.35 minutes
Answer: A.12.5 minutes.
Explanation: If the distance between the two houses is D. Then
Speed of Danny = (D/25)
Speed of Steve = (D/50) [ Steve takes 50 minutes to reach Danny's house. double the time taken by Danny)
Obviously speed of Danny is Twice that of Steve.
Now in order to cover distance (D/2) [They meet in middle], Steve will take:
(D/2) / (D/50) = 25 minutes.
Distance is same and Danny's speed is twice of Steve. Thus he will take 12.5 minutes to cover this same distance.
Steve take 25-12.5 = 12.5 minutes longer.
A is the answer.
Question: 100 is increased by 50%. Find the final number.
A.100
B.110
C.150
D.155
Answer: C.150
Explanation: Final number = Initial number + 50%(original number) = 100 + 50%(100) = 100 + 50 = 150.
Answer C
Question: While working alone at their constant rates, computer X can process 240 files in 12 hours, and computer Y can process 240 files in 6 hours. If all files processed by these computers are the same size, how many hours would it take the two computers, working at the same time at their respective constant rates, to process a total of 240 files?
A.3
B.3.5
C.4
D.4.5
Answer: C.4
Explanation: Both computers together process files at a rate of 240/12 + 240/6 = 20+40 = 60 files per hour.
The time required to process 240 files is 240/60 = 4 hours
The answer is C.
Question: What is the smallest integer that satisfies the inequality (x - 3)/ (x^2 - 8x - 20) > 0> 0?
A.-2
B.10
C.3
D.-1
Answer: D.-1
Explanation: Explanatory Answer
Let us factorize the denominator and rewrite the expression as x−3 /(x−10)(x+2) > 0
Equate each of the terms of the expression to zero to identify the values of x that are relevant to test whether the inequality holds good.
The values that are relevant to us are x = 3, x = 10 and x = -2.
Let us arrange these values in ascending order: -2, 3 and 10.
The quickest way to solve inequalities questions after arriving at these values is verifying whether the inequality holds good at the following intervals.
Interval 1: x < -2.
Pick a value in that range and check whether the inequality holds good.
Let us take x = -10. When x = -10, x−3 /(x−10)(x+2) < 0; the inequality DOES NOT hold good in this interval.
Interval 2: -2 < x < 3.
Let us take x = 0. When x = 0, x−3/(x−10)(x+2) = 0−3 /(0−10)(0+2) > 0; the inequality holds good in this interval.
The least integer value that x can take if x > -2 is x = -1.
So, the correct answer is -1. Choice D.
Remember: We have to find out the least integer value. And we have arrived at -1.
Do, not waste time computing the entire range of values of x that satisfy the inequality.
Note: In any inequality question, when the question asks us to determine the intervals in which the inequality holds good, we have to eliminate values of x that will result in the denominator becoming zero.
Choice D
Question: If r = 199,999 and s = 991,999, which of the following is the units digit of r^4 + s^4?
A.0
B.1
C.2
D.8
Answer: C.2
Explanation: The exponents of 9 cycle between 9 (odd exponents) and 1 (even exponents).
Then the sum of r^4+s^4 will have the units digit of 1+1 = 2 as a units digit.
The answer is C.
Question: What is the area of a square with perimeter 4P ?
A. p^2
B. 4P
C. P^2/4
D. P/16
Answer: A. p^2
Explanation: Each side is p
A = (p)^2
Answer A
Question: Rahul and Bharti are partners in a business. Rahul contributes 1/4th capital for 15 months and Bharti received 2/3 of profit. For how long Bharti money was used.
A.8 months
B.10 months
C.11 months
D.17 months
Answer: B.10 months
Explanation: Explanation:
Let the total profit be Rs. Z
Bharti's share = (2/3)Z
Rahul's Share = Z-(2/3)Z = Z/3
Rahul:Bharti = Z/3:(2/3)Z = 1:2
Now let the total capital be Rs X, and Bharti capital was used for Y months
then, Rahul capital will be (1/4)X and Bharti capital wil be X-(1/4)X = 3X/4
14X∗15/ 3/4X∗Y=1/2
Y=15∗2/3=10
So Bharti's money was used for 10 months
Option B
Question: By selling 50 meters of cloth. I gain the selling price of 15 meters. Find the gain percent?
A.35%
B.30%
C.40%
D.42 6/7%
Answer: D.42 6/7%
Explanation: Explanation:
SP = CP + g
50 SP = 50 CP + 15 SP
35 SP = 50 CP
35 --- 15 CP gain
100 --- ? => 42 6/7%
Answer IS D
Question: If n divided by 7 has a remainder of 2, what is the remainder when 2 times n is divided by 7?
A.1
B.2
C.3
D.4
Answer: D.4
Explanation: As per question => N=7P+2 for some integer p
hence 2N => 14Q + 4 => remainder => 4 for some integer Q
Alternatively => N=2 > 2N=> 4 =>4 divided by 7 will leave a remainder 4
hence D
Question: A bag contains 2 red, 3 green and 2 blue balls. 2 balls are to be drawn randomly. What is the probability that the balls drawn contain no blue ball?
A.5⁄7
B.10⁄21
C.2⁄7
D.11⁄21
Answer: B.10⁄21
Explanation: Reqd probability = 5C2/7C2=5×4/7×6=10/21
Answer B
Question: If the product of the integers r, s, t and u is 770, and if 1 < r< s< t< u, what is the value of r+ u?
A.10
B.13
C.16
D.18
Answer: B.13
Explanation: 770 = 2 * 5 * 7 * 11
So r= 2, s= 5, t= 7, u= 11
r+ u= 2 + 11 = 13
Answer - B
Question: At 6'o clock clock ticks 6 times. The time between first and
last ticks was 30sec. How much time it takes at 11'o clock.
A.60sec
B.62sec
C.66sec
D.64sec
Answer: A.60sec
Explanation: At 6'0 clock, clock ticks 6 times.
So, there must be 5 intervals between clock ticks.
Time Between first and last ticks = 30sec
So, 1 interval = 30/5 = 6sec
So 6'o clock 5 *6=30sec
7'o clock 6 *6=36sec
.
.
.
10'o clock 9 *6=54sec
11'o clock 10*6=60sec
So, 60sec at 11'o clock.
ANSWER:A
Question: In how many different R ways can 4 ladies and 4 gentlemen be seated at a round table so that all ladies sit together?
A.70
B.288
C.576
D.10,080
Answer: C.576
Explanation: Treat the 4 ladies as one object, now you have 5 objects to arrange around a table (m1,m2,m3,m4,women). This can be done in (5-1)! ways
And there are 4! ways to arrange ladies among themselves
Answer R= (4!)^2 = 576 or C
Question: The integers 1, 2, …, 40 are written on a blackboard. The following operation is then repeated 39 times: In each repetition, any two numbers, say a and b, currently on the blackboard are erased and a new number a + b – 1 is written. What will be the sum of the numbers left on the board at the end?
A.820
B.821
C.781
D.819
Answer: C.781
Explanation: Explanation :
Initial sum of the numbers is 1 + 2 + …40.
Initial sum = 40 * 41/2 = 820. (A.P. with common difference 1 and 1st term 1, last term 40).
Two numbers, a, b are erased and replaced by a+b-1, that means, the sum is now 819.
This is done 39 times. So, sum after 39 time replacement is 820 – 39 = 781.
Answer : C
Question: If December 3rd, 1999 is a Friday, what day is January 7th, 2000?
A.Wednesday
B.Thursday
C.Friday
D.Saturday
Answer: C.Friday
Explanation: There is difference of 35 days from Dec. 3rd 1999 to Jan. 7th 2000.
35/7 has a remainder of 0.
Jan. 7th is: Friday + 0 days = Friday
The answer is C.