RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: This topic is locked. If you want to discuss this question please re-post it in the respective forum.
If y ≠ 3 and 3q/y is a prime integer greater than 2, which of the following must be true?
I. q = y
II. y = 1
III. q and y are prime integers.
A. None
B. I only
C. II only
D. III only
Answer: A. None
Explanation: 3q/y and if q=y then ans is 3 and 3 is prime number, which is greater than 2. so ans must be B. Please post OA.
Question: In the xy-plane, the point (-2, -1) is the center of a circle. The point (1, -1) lies inside the circle and the point (-2, 4) lies outside the circle. If the radius r of the circle is an integer, then r =
A.6
B.5
C.4
D.3
Answer: C.4
Explanation: An easy way to solve this question will be just to mark the points on the coordinate plane.
You'll see that the distance between the center (-2, -1) and the point inside the circle (1, -1) is 3 units
(both points are on y=-1 line so the distance will simply be 1-(-2)=3)
So the radius must be more than 3 units.
The distance between the center (-2,-1) and the point outside the circle (-2,4) is 5 units
(both points are on x=-2 line so the distance will simply be 4-(-1)=5)
So the radius must be less than 5 units, which implies 3 < r < 5, thus as r is an integer then r=4.
Answer: C.
Question: Pablo plays 3 rounds of a game, in which his chances of winning each round are 1/3 ,1/6 , and 1/n, respectively. If n ≠ 0, what is the probability that Pablo wins the first two rounds, but loses the third?
A.1/18n
B.(n-1)/18n
C.1/2n
D.(n+2)/2n
Answer: B.(n-1)/18n
Explanation: 1/3 * 1/6 * (1-1/n)
= 1/18 * (n-1)/n
= (n-1)/18n
Answer - B
Question: Arun and Varun started business in partnership investing Rs. 20,000 and Rs. 15,000 respectively. After six months, Akhil joined them with Rs. 20,000. What will be Varun's share in the total profit of Rs. 25,000 earned at the end of 2 years from the starting of the business ?
A.7500
B.7502
C.7512
D.2988
Answer: A.7500
Explanation: Arun : Varun : Akhil = (20000 x 24) : (15000 x 24) : (20000 x 18) = 4:3:3
B's share = 25000 x 3/10 = Rs. 7500
Answer: A
Question: he ratio between the sale price and the cost price of an article is 3:1. What is the ratio between the profit and the cost price of that article?
A.2:1
B.2:9
C.2:4
D.2:1
Answer: A.2:1
Explanation: Let C.P. = Rs. x and S.P. = Rs. 3x.
Then, Gain = Rs. 2x
Required ratio = 2x : x = 2:1.
Answer:A
Question: Boy sells a book for Rs. 630 he gets a loss of 10 %, To gain 10%, what should be the SP?
A.430
B.450
C.550
D.770
Answer: D.770
Explanation: Cost price = 630/90 x 100 = 700
To gain 10% = 700 x 10/100 = 70
SP = CP + gain = 700 + 70 = 770
Answer :D
Question: What is the difference between the place values of two 1's in the numeral 135.21
A.99.999
B.100.2
C.134
D.99.99
Answer: D.99.99
Explanation: Required difference = 100-0.01 = 99.99
Answer is D
Question: A company, Chauncy Co., has an annual travel budget of $57,000. The accounting department estimates that transportation expenses will increase 5 percent in the coming year, and nontransportation travel expenses will increase by 15 percent in the coming year. Last year, Chauncy Co. spent $19,500 on transportation-related expenses, and $35,000 on nontransportation travel expenses. If the annual travel budget does not increase this year, and if the accounting department’s estimates are correct, how far over the annual travel budget will expenses be this year?
A.$3,725
B.$500
C.$4,225
D.$5,725
Answer: A.$3,725
Explanation: annual travel budget of $57,000
Let, Transportation expenses = T = 19500
and Non-Transportation expenses = N=35000
i.e. Increased Transportation expenses = 1.05T = 20475
and Increased Non-Transportation expenses = 1.15N = 40250
Total Expense = 20475+40250 = 60725
Expense over Budget = Budget - expense = 57000-60725 = 3725
Answer: Option A
Question: At what time between 2 and 3 o'clock will the hands of a clock be together?
A.(10 + 10/11) min past 8
B.(10 + 10/11) min past 2
C.(10 + 10/11) min past 3
D.(10 + 10/11) min past 1
Answer: B.(10 + 10/11) min past 2
Explanation: At 2 o'clock, the hour hand is at 2 and the minute hand is at 12, i.e. they are 10 min spaces apart.
To be together, the minute hand must gain 10 minutes over the hour hand.
Now, 55 minutes are gained by it in 60 min.
10 minutes will be gained in min. = min.
The hands will coincide at min. past 2.
Answer: B
Question: A man misses a bus by 40 minutes if he travels at 30 kmph. If he travels at 40 kmph, then also he misses the bus by 10 minutes. What is the minimum speed required to catch the bus on time?
A.11
B.45
C.77
D.44
Answer: B.45
Explanation: Let the distance to be travelled to catch the bus be x km
x/30 - x/40 = 30/60 => (4x - 3x)/120 = 1/2 => x = 60 km
By traavelling 30 kmph time taken = 60/30 = 2 hours
By taking 2 hours, he is late by 40 min. So, he has to cover 60 km in at most speed = 60/(4/3) = 45 kmph.
Answer: B
Question: A taxi company costs $2.75 for the first quarter-mile and 12.5 cents for each additional quarter mile. What is the maximum distance you can travel with $6.50?
A.4 miles
B.5 3/4 miles
C.6 1/2 miles
D.7 3/4 miles
Answer: D.7 3/4 miles
Explanation: Use reverse calculation-
Total Cost = Fixed Cost ( For 1/4 miles ) + Variable cost ( Distance Travelled )
Or, 6.50 = 2.75 + 0.125 * d
Or, 3.75 = d/8
Or, d = 30 quarter miles
So, Total Distance = ( 30 + 1 ) Quarter miles
So, Distance = 31/4 => 73/4 miles
Hence answer will be (D)
Question: A train 240 m long passed a pole in 24 sec. How long will it take to pass a platform 660 m long?
A.22
B.90
C.277
D.278
Answer: B.90
Explanation: Speed = 240/24 = 10 m/sec.
Required time = (240 + 660)/10 = 90 sec.
Answer: B
Question: Rajesh solved 80 per cent of the questions in an examination correctly. If out of 41 questions solved by Rajesh 37 questions are correct and of the remaining questions out of 8 questions 5 questions have been solved by Rajesh correctly then find the total number of questions asked in the examination.
A.75
B.65
C.60
D.Cannot be determined
Answer: B.65
Explanation: Suppose there are 8x questions a part from the 41 questions.
Then, 37+5x/41+8x=80%=45
⇒ 185 + 25x = 164 + 32x ⇒ 7x= 21 ⇒ x = 3
∴ Total no.of questions = 41 + 8x = 65
Answer B
Question: On rainy mornings, Mo drinks exactly N cups of hot chocolate (assume that N is an integer). On mornings that are not rainy, Mo drinks exactly 5 cups of tea. Last week Mo drank a total of 22 cups of tea and hot chocolate together. If during that week Mo drank 8 more tea cups than hot chocolate cups, then how many rainy days were there last week?
A.2
B.4
C.3
D.5
Answer: B.4
Explanation: T= the number of cups of tea
C= the number of cups of hot chocolate
T+C = 22 T-C=8 -> T= 15. C=7.
Mo drinks 5 cups of tea a day then number of days that are not rainy = 15/5 = 3
So number of rainy days = 7-3 = 4
B is the answer.
Question: Two trains of equal length 120 metres move in the same direction. The faster train completely
overtakes the slower one in 15 seconds. If the slower train were to move at half its speed, the over
taking would take in 10 seconds. At what speeds are the 2 trains moving ?
A.24,22
B.32,16
C.30,18
D.28,14
Answer: B.32,16
Explanation: Explanation :
The total distance covered for over taking = length of the two trains = 120 +120 = 240
Speed of faster train be x m/s and slower train be y m/s
In the first case Relative speed = x-y
Relative Speed = Distance / Time taken = x-y = 240/15 = 16 m/s(1)
In the second case, the slower train moves at half its speed
Relative Speed = x-0.5y = 240/10 = 24 m/s ..(2)
Solving equation 1 & 2 we get x = 32 and y = 16 .
The speed of the faster and slower trains are 32 m/s and 16 m/s respectively
Answer : B
Question: Train A left Centerville Station, heading toward Dale City Station, at 3: 00 p.m. Train B left Dale City Station, heading toward Centerville Station, at 2: 20 p.m. on the same day. The trains rode on straight tracks that were parallel to each other. If Train A traveled at a constant speed of 30 miles per hour and Train B traveled at a constant speed of 10 miles per hour, and the distance between the Centerville Station and Dale City Station is 90 miles, when did the trains pass each other?
A.4: 45 p.m.
B.5: 00 p.m.
C.5: 20 p.m.
D.4: 20 p.m.
Answer: D.4: 20 p.m.
Explanation: the distance travelled by the train A in first 20 minutes will be 10.
The distance which will be remaining is 80.
Now both trains are running in opposite direction.Their speed will be added so 40.
Time at which they will meet =80/40=2
time of train B will be 2:20 +2=4:20
Hence answer is D.Hope i am correct
Question: Mrs. Rodger got a weekly raise of $155. If she gets paid every other week, write an integer describing how the raise will affect her paycheck.
A.$ 145.
B.$ 146
C.$ 147
D.$ 155
Answer: D.$ 155
Explanation: Solution:
Let the 1st paycheck be x (integer).
Mrs. Rodger got a weekly raise of $ 155.
So after completing the 1st week she will get $ (x+155).
Similarly after completing the 2nd week she will get $ (x + 155) + $ 155.
= $ (x + 155 + 155)
= $ (x + 310)
So in this way end of every week her salary will increase by $ 155.
Answer D
Question: A = {0, 1, -3, 6, -8, -10}
B = {-1, 2, -4, 7, 6, -9}
If a is a number that is randomly selected from Set A, and b is a number that is randomly selected from Set B, what is the probability that ab < 0?
A.1/4
B.1/3
C.5/13
D.5/12
Answer: D.5/12
Explanation: For the product of 2 numbers to be negative either of them must be positive or negative:
P(positive, negative) = 2/6*3/6 = 6/36;
P(negative,positive ) = 3/6 * 3/6 = 9/36
P = 6/36 + 9/36
P = 15/36
P = 5/12
Answer: D
Question: How many integers between 0 and 1000 DO NOT contain the integer 1
A.727
B.728
C.758
D.748
Answer: B.728
Explanation: from 1 to 99 = 19 integers having 1
from 101 to 199 = all are having 1
similarly 201-299, 301-399, 401-499,.....so on, will have 19 integers having 1
Answer = 1000 - (19*9 + 99 + 2) // 2 is added for 100 and 1000
= 728
ANSWER:B
Question: It takes John 10 minutes to walk to the car park and 45 to drive to work. At what time should he get out of the house in order to get to work at 9:00 a.m.?
A.5:44
B.7:35
C.7
D.5
Answer: B.7:35
Explanation: The time it takes John to get to work: time to walk to car park + time to drive
25 + 45 = 70 minutes = 1 hour and 10 minutes
John needs to get out of the house 1 hour and 10 minutes before 9:00 am at
9:00 - 1:10 = 7:35 a.m.
B
Question: When 0.535353 ... is converted into a fraction, the result is
A.5/17
B.20/9
C.53/99
D.53/100
Answer: C.53/99
Explanation: Explanation:
0.535353..... = 0.53
= 53/99
ANSWER: C
Question: In expressing a length 81.489 km as nearly as possible with three significant digits, find the percentage error?
A.0.075%
B.0.156%
C.0.013%
D.0.048%
Answer: C.0.013%
Explanation: Error = 81.5-81.489 = 0.011
Required percentage = (0.011/81.489)*100 = 0.013%
Answer is C
Question: Find the odd man out 15, 25, 30, 34, 40, 65, 75.
A.15
B.34
C.50
D.75
Answer: B.34
Explanation: Each of the numbers is multiple of 5 except 34, not divisible by 5.
3*5=15
5*5=25
8*5=40
13*5=65
14*5=70
ANSWER: B
Question: Find the circumference and area of radius 13 cm.
A.124 cm²
B.531 cm²
C.354 cm²
D.584 cm²
Answer: B.531 cm²
Explanation: Area of circle = πr²
= 22/7 × 13 × 13 cm²
= 531 cm²
ANSWER:B
Question: Find 40 % of 240
A.96
B.94
C.86
D.74
Answer: A.96
Explanation: We know that R % of m is equal to R/100 × m.
So, we have 40 % of 240
40/100 × 240
= 96
Answer:A
Question: Car X began traveling at an average speed of 35 miles per hour. After 72 minutes, car Y began traveling at an average speed of 70 miles per hour. When both cars had traveled the same distance, both cars stopped. How many miles did car X travel from the time car Y began traveling until both cars stopped?
A.15
B.20
C.40
D.42
Answer: D.42
Explanation: Car Y began travelling after 72 minutes or 1.2 hours.
Let t be the time for which car Y travelled before it stopped.
Both cars stop when they have travelled the same distance.
So,
35(t+1.2) = 70t
t=1.2
Distance traveled by car X from the time car Y began traveling until both cars stopped is
35 x 1.2
= 42 miles
Answer:- D
Question: Krishan and Nandan jointly started a business. Krishan invested three times as Nandan did and invested his money for double time as compared to Nandan. Nandan earned Rs. 4000. If the gain is proportional to the money invested and the time for which the money is invested then the total gain was?
A.228878
B.27771
C.28867
D.28,000
Answer: D.28,000
Explanation: 3:1
2:1
------
6:1
1 ----- 4000
7 ----- ? => Rs.28,000
Answer:D
Question: On flipping 3 coins together what is the outcomes for at least three head and three tail?
A.1/7
B.2/8
C.3/11
D.4/13
Answer: B.2/8
Explanation: Sample space, S = {HHH, HHT, HTH, THH, TTH, THT, HTT, TTT}
Favorable outcomes for at least two heads
= favorable outcomes for exactly two heads and favorable outcomes for more than two heads
= {HHH,TTT}
2/8
B
Question: Find the area of trapezium whose parallel sides are 20 cm and 18 cm long, and the distance between them is 15 cm.
A.276
B.209
C.285
D.267
Answer: C.285
Explanation: Area of a trapezium = 1/2 (sum of parallel sides) * (perpendicular distance between them)
= 1/2 (20 + 18) * (15)
= 285 cm2
Answer: C
Question: John takes 6 hrs to print 32 pages. Peter takes 5hrs to print 40 pages. In how many hours they will print 110 pages together ?
A.7 hours 15 minutes
B.8 hours 15 minutes
C.9 hours
D.10 hours 15 minutes
Answer: B.8 hours 15 minutes
Explanation: Ram can type 32/6 pages per hour
Shaam can type 8 pages per hourThey can type 32/6 + 8 = 40/3 pages per hour
So they will take 110/40 × 3 = 33/4 hours or 8 hours 15 minutes
B)
Question: A straight line in the xy-plane has a slope of 2 and a y-intercept of 2. On this line, what is the x-coordinate of the point whose y-coordinate is 540 ?
A.249
B.498
C.676
D.269
Answer: D.269
Explanation: slope of 2 and a y-intercept of 2
y-coordinate is 540
y = 2x + 2
538 = 2x
x = 269
Answer:
D. 269
Question: A train running at the speed of 60 km/hr crosses a pole in 9 seconds. What is the length of the train?
A.288 metres
B.557 metres
C.887 metres
D.150 metres
Answer: D.150 metres
Explanation: Speed=(60 * 5/18) m/sec = (50/3) m/sec Length of the train = (Speed x Time) = (50/3 * 9) m = 150 m.Answer: D
Question: Which one of the following numbers is exactly divisible by 11?
A.235641
B.245642
C.315624
D.415624
Answer: D.415624
Explanation: (4 + 5 + 2) - (1 + 6 + 3) = 1, not divisible by 11.
(2 + 6 + 4) - (4 + 5 + 2) = 1, not divisible by 11.
(4 + 6 + 1) - (2 + 5 + 3) = 1, not divisible by 11.
(4 + 6 + 1) - (2 + 5 + 4) = 0.
So, 415624 is divisible by 11
ANSWER:D
Question: A boy wants to go abroad by boat and return by flight. He has a choice of 5 different boat to go and 5 flight to return. In how many ways, can the boy perform his journey?
A.20
B.25
C.30
D.40
Answer: B.25
Explanation: Ans.(B)
Sol. Number of choices to go by ship = 5 Number of choices to return by airline = 5 From, fundamental principle, total number of ways of performing the journey = 5 x 5 = 25 ways
Question: What is the average of first 21 multiples of 7 ?
A.55
B.66
C.77
D.88
Answer: C.77
Explanation: Explanation:
Required average = 7(1+2+….+21) / 21
(7/21)X ( (21×22) / 2 ) (because sum of first 21 natural numbers)
= 77
Answer: C
Question: The digit sum of the year 2007 is 2 + 0 + 0 + 7 = 9, which is a square number. How many years during the twenty-first century have a square digital sum?
A.13
B.14
C.15
D.16
Answer: D.16
Explanation: The twenty-first century runs from the year 2001 to 2100 inclusive, so with the
exception of the year 2100, for which the digital sum is three anyway, the first two
digits of all the other years are fixed as 20. Hence for the sum of all the digits to be
square the sum of the last two digits number be two less than a perfect square.
As the maximum sum of the last two digits is 18, the greatest sum will be 20.
Therefore we can obtain digital sums of 4, 9, or 16, with the last two digits adding to
2, 7, or 14 respectively.
4: 2002, 2011, 2020
9: 2007, 2016, 2025, 2034, 2043, 2052, 2061, 2070
16: 2059, 2068, 2077, 2086, 2095
That is, there are sixteen years during the twenty-first century for which the digital
sum is square.
ANSWER:D
Question: If x=kc and y=kt,then y+x =?
A.k(t+c)
B.k(c-t)
C.c(k-t)
D.t(k-c)
Answer: A.k(t+c)
Explanation: Just put in the given values of y and x
y - x = kt - kc
Now take k common
y - x = k(t + c)
You get (A) as your answer.
Question: Simplify: 997 x 997
A.999991
B.994009
C.999994
D.997009
Answer: B.994009
Explanation: 997 x 997 = (1000 - 3)(1000 - 3)
= 1000000 +9-3000-3000
= 994009
Answer is B
Question: If |r|=−r, which of the following must be true?
A.x≥0
B.r≤0
C.x2>x
D.x3<0
Answer: B.r≤0
Explanation: |r| =-r means absolute value of r is equal to negative of r. Since absolute value cannot be negative hence negative of r should result in a non negative number. It means r is a non positive number i.e. r<0. Answer is B
Question: If the selling price of 80 articles is equal to the cost price of 40 articles, then the loss or gain percent is:
A.30%
B.35%
C.50%
D.55%
Answer: C.50%
Explanation: Let C.P. of each article be Re. 1.
Then, C.P. of 80 articles = Rs. 80;
S.P. of 80 articles = Rs. 40.
Loss % = 40/80 * 100 = 50%
ANSWER:C
Question: The measures of the 2 acute angles of a triangle are in the ratio of 1 : 8. What arethe measures of the 2 angles?
A.20°
B.80°
C.110°
D.120°
Answer: B.80°
Explanation: If the ratio of the two angles is 1:8, then the measures of two angles can be written as x and 8x. Also the two acute angles of a triangle is equal to 90°. Hence
x + 8x = 90
9x = 90
x = 10
Measures of the two acute angles are
x = 1 × 10 = 10°
8x = 8 × 10 = 80°
B
Question: For all positive integers n and m, the function A(n) equals the following product:
(1 + 1/2 + 1/2^2)(1 + 1/3 + 3^2)(1 + 1/8 + 8^2)…(1 + 1/p_n + 1/p_n^2), where p_n is the nth smallest prime number, while B(m) equals the sum of the reciprocals of all the positive integers from 1 through m, inclusive. The largest reciprocal of an integer in the sum that B(25) represents that is NOT present in the distributed expansion of A(5) is
A.1/3
B.1/5
C.1/6
D.1/7
Answer: A.1/3
Explanation: For all positive integers n and m,
A(n) = (1 + 1/2 + 1/2^2)(1 + 1/3 + 3^2)(1 + 1/5 + 5^2)…(1 + 1/p_n + 1/p_n^2), where p_n is the nth smallest prime number,
note:i think there's a typo in the above function, A(n) could be (1 + 1/2 + 1/2^2)(1 + 1/3 +1/3^2)(1 + 1/5 +1/5^2)…(1 + 1/p_n + 1/p_n^2)
B(m) = sum of the reciprocals of all the positive integers from 1 through m, inclusive.
A(5), here 5 represents the 5th smallest prime number; the 5th smallest prime number is 11 {2, 3, 5, 7, 11, ...}
A(5) = (1 + 1/2 + 1/2^2)(1 + 1/3 + 3^2)(1 + 1/5 + 5^2)(1 + 1/7 + 1/7^2)(1 + 1/11 + 11^2)
The distributed expansion of A(5) = 1 + 1/2 + 1/3 + 1/4 + 1/5 + 1/6 +1/7 + 1/9+ 1/10 + 1/11 +1/12 + 1/14+ ...
missing numbers are 1/8, 1/13, 1/16, ....
B(25) = (1 + 1/2 + 1/3 + 1/4 + ... + 1/16 + 1/17 + ... + 1/25)
here the largest reciprocal is 1 and the reciprocals are arranged in descending order based on their values
The largest reciprocal that present in B(25) but not in A(5) is 1/3
Answer A
Question: A mathematics teacher tabulated the marks secured by 35 students of 8th class. The average of their marks was 72. If the marks secured by Reema was written as 46 instead of 96 then find the correct average marks up to two decimal places.
A.73.41
B.74.31
C.73.42
D.73.43
Answer: C.73.42
Explanation: Total marks = 35 x 72 =2520
Corrected total marks = 2520 - 46 + 96 =2570
Correct Average = 2570/35 = 73.42
Answer : C
Question: If x is an even integer, then which of the following is a true statement?
A.x is a prime number
B.(x2 + 4) is an even integer
C.x is a Composite number
D.(x2 - 1) is an even integer
Answer: B.(x2 + 4) is an even integer
Explanation: Explanation:
(x2 + 4) is an even integer
Answer: Option B
Question: A grocery store recently raised the price of flour by 25% over the original price. If the owner then had a sale advertising 10% off, what would be the sale price if the original price was $20?
A. $21.00
B. $21.50
C. $22.00
D. $22.50
Answer: D. $22.50
Explanation: sale price = (original price + 25% increase) - 10% decrease
price = [20 * (125/100)] * (90/100) = 20 * (1.25) * (.90) = 25 * .9 = 22.50
The answer is D.
Question: Divide 71 into 2 parts such that 1 part exceeds the other by 8. What are the 2 no.'s in that part?
A.27
B.28
C.31
D.35
Answer: C.31
Explanation: Let $let n$ be the smaller and 71 - n be the larger number. Now, since the larger number exceeds the smaller number by 7, we can form the equation
larger number – smaller number = 7
which is equivalent to
Simplifying, we have 71 - 2n = 7. This gives us 2n = 78 which implies that the larger number is . The smaller is 71-39=31.
C
Question: A train passes a man standing on the platform. If the train is 140 meters long and its speed is 72 kmph, how much time it took in doing so?
A.6 Â½ sec
B.6 Â½ sec
C.9 Â½ sec
D.7 sec
Answer: D.7 sec
Explanation: D
7 sec
D = 140
S = 72 * 5/18 = 20 mps
T = 140/20 = 7 sec
Question: The average of five results is 45 and that of the first four is 45. The fifth result is?
A.45
B.88
C.77
D.66
Answer: A.45
Explanation: 5 * 45 â€“ 4 * 45
= 45
Answer: A
Question: Priya bought a fish last week. She was going to measure it but realized that her ruler was not long enough. She was able to measure the head and discovered that it was 12cm long; she then measured the tail and found that it was the length of the head plus one third of the length of the body. If the body was the length of the head plus the tail, what is the total length of the fish?
A.58
B.45
C.72
D.63
Answer: C.72
Explanation: Let us take H=Length of the head
T=Length of the tail
B=length of the body
Given that H=12 cms.
T=H+1/3 B => T=12+1/3B
Let this be the first equation
B=H+T
substituting the value of H and T here we will get
B=12+12+1/3B
=> B=24+1/3B
Therefore,B=36 cm
Substituting this in T we get
T=12+1/3(36)
T=12+12 =24
So now that you got all the values add
H=12 cm
B=36 cm
T= 24 cm
and the answer is 72 cm
ANSWER:C
Question: A certain sum of money doubles itself in 10 years in how much many years will it trible itself at the same rate?
A.7 1/2 years
B.20 years
C.15 years
D.38 years
Answer: B.20 years
Explanation: 100 ---- 100 --- 10
100 --- 10
--------------------
300 ---- 20 years
ANSWER:B
Question: A watch which gains 5 seconds in 3 minutes was set right at 7 a.m. In the afternoon of the same day, when the watch indicated quarter past 4 O’clock, the true time is –
A.4 p.m.
B.59 7⁄12 minutes past 3
C.58 7⁄11 minutes past 3
D.2 3⁄11 minutes past 4
Answer: A.4 p.m.
Explanation: Time from 7 a.m. to quarter pas 4
= 9 hours 15 min. = 555 min.
Now, 37⁄12 min. of this watch = 3 min. of the correct watch.
555 min.of this watch = (3×12/37×555) min.
= (3×12/37×55560) hrs. = 9 hrs. of the correct watch.
Correct time is 9 hours after 7 a.m. i.e., 4 p.m.
Answer A
Question: A boy and a girl appear for an interview against 2 vacant posts in an office. The probability of the boy's selection is 1/5 and that of the girl's selection is 1/3. What is the probability that only 1 of them is selected?
A.1/3
B.2/5
C.3/5
D.4/7
Answer: B.2/5
Explanation: Probability that only one of them is selected = (prob. that brother is selected) × (prob. that sister is not selected) + (Prob. that brother is not selected) × (Prob. that sister is selected)
= = 2/5
B
Question: A seven-digit phone number is divisible by 8. After adding the two digits of the area code the number is not divisible by 8, which of the following cannot be the area code?
A.07.
B.05.
C.08.
D.04.
Answer: C.08.
Explanation: Given that 7 digit number is divisible by 8
we know any number will not be divisible by 8 if the sum of all digits of the number is not the multiple of 8.
Hence looking at the option we can say that the number that should be added to the seven digit number must be 08 as adding it will make it divisible by 8... hence answer is C