RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: The grade point average of the entire class is 90. If the average of one third of the class is 96, what is the average of the rest?
A.92
B.89
C.88
D.87
Answer: D.87
Explanation: Let us take number of students on the class as 'x'.
avg grade point = sum of all grade points/x
sum of all grade points = avg grade point*x = 90x
average of one third of the class = 96 = sum of one third grade points of the class/(x/3)
sum of one third grade points of the class = 96*(x/3) = 32x
sum of rest two third grade points of the class = sum of all grade points - sum of one third grade points of the class
sum of rest two third grade points of the class = 90x-32x = 58x
avg of two third of the class = sum of rest two third grade points of the class/(x*2/3) = 58x/(2x/3) = 29*3 = 87.
Hence, answer is D
Question: In how many ways can the letters of the word CAVED be arranged in a row so that the vowels appear in alphabetic order?
A.60
B.30
C.120
D.240
Answer: A.60
Explanation: Two letters can be arranged in 2! ways.
only one combination EIU is required.
5 letters can be arranged in 5! ways.
thus 5!/ 2! * 1 = 60.
A
Question: A and B invests Rs.10000 each, A investing for 8 months and B investing for all the 12 months in the year. If the total profit at the end of the year is Rs.25000, find their shares?
A.Rs.10000, Rs.15020
B.Rs.10000, Rs.15700
C.Rs.10000, Rs.15090
D.Rs.10000, Rs.15000
Answer: D.Rs.10000, Rs.15000
Explanation: The ratio of their profits A:B
= 8:12 = 2:3
Share of A in the total profit
= 2/5 * 25000
= Rs.10000 Share of A in the total profit = 3/5 * 25000
= Rs.15000
Answer: D
Question: Of the following values of n, the value of (-1/4)^(-n) will be greatest for n =
A.3
B.0
C.2
D.-2
Answer: C.2
Explanation: imo -2
(-1/4)^-2=
1/(1/16)=16
oops i meant 2
C
Question: A is twice as fast as B. If B alone can do a piece of work in 18 days, in what time can A and B together complete the work?
A.10
B.16
C.18
D.6
Answer: D.6
Explanation: A can do the work in 18/2 i.e., 9 days.
A and B's one day's work = 1/9+ 1/18 = (2 + 1)/18 = 1/6
So A and B together can do the work in 6 days.
Answer: D
Question: A train does a journey without stoppage in 8 hours, if it had travelled 5 km/h faster, it would have done the journey in 6 hours 40 minutes. Find its original speed.
A.25 km/h
B.40 km/h
C.45 km/h
D.36.5 km/h
Answer: A.25 km/h
Explanation: Let original speed = S km/h
Here, distance to be covered is constant
∴ S × 8 = (S + 5)(20⁄3)
⇒ 8S - 20⁄3S = 100⁄3 ⇒ S = 100⁄4 = 25 km/h
Answer A
Question: In how many ways can the letters of the word 'LEADER' be arranged ?
A.360
B.72
C.144
D.760
Answer: A.360
Explanation: The word 'LEADER' contains 6 letters, namely 1L, 2E, 1A, 1D and 1R.
∴ Required number of ways = 6!/(1!)(2!)(1!)(1!)(2!) = 360.
Answer is A
Question: If n is the greatest positive integer for which 2^n is a factor of 8!, then n =?
A.2
B.4
C.6
D.8
Answer: C.6
Explanation: 8! = 40320
E. 2^10 = 512 (40320/512) - this is not a factor of 8!
D. 2^8 = 256 (40320/256) - this is not a factor of 8!
C. 2^6 = 64 (720/64) - this is a factor of 8!
C is answer
Question: In a class ,there are 15 boys and 10 girls .one student is selected at random. The probability that one girl is selected,is:
A.10/25
B.2/5
C.15/25
D.3/25
Answer: B.2/5
Explanation: Total number of students = 10+15= 25
no.of girls in a class = 10
probability of one girl is selected = 10/25= 2/5
Answer is B
Question: What is the tenth digit of (4!*3! + 4!*2!)/3?
A.5
B.7
C.9
D.1
Answer: C.9
Explanation: (4!*3! + 4!*2!)/2
=4!(3! + 2!)/2
=24 (6+2)/2
=96
Units digit of the above product will be equal to 9
Answer C
Question: The probability that A speaks truth is 15/23 and that of B speaking truth is 17/29. What is the probability that they agree in stating the same fact?
A.182/395
B.129/289
C.197/353
D.479/667
Answer: D.479/667
Explanation: If both agree stating the same fact, either both of them speak truth of both speak false.
Probability = 15/23 * 17/29 + 14/23 * 16/29
= 255/667 + 224/667 = 479/667
ANSWER:D
Question: If x is a positive integer, what is the units digit of (24)^(2x+1)(33)^(x+1)(17)^(x+2)(9)^(2x)
A.4
B.6
C.7
D.8
Answer: D.8
Explanation: To find the units digit of the above (24)^(2x+1)(33)^(x+1)(17)^(x+2)(9)^(2x) , find the units digit of each term possible .
24^2x . 24 --> Units digit of (24^2)^X = 6^X = 6 multiplied by last digit of 24 = 4
33^x . 33 --> Units digit of 33^x . 3 --> 3,9,7,1 multiplied by 3
17^x. 17^2 --> Units digit of 17^x. 9 (units digit of 7^2)--> 7,9,3,1 multiplied by 9
9^2x --> Units digit of 81^x = 1
If you observe 2nd and 3rd expression above and multiply both you will always get 1 for units digit of 33^x multiplied by 17^x ( because 3*7, 9*9,7*3,1*1 all end in 1 for the same value of x) . Thus you have 3 and 9 from 2nd and third expression above.
So the units digit of the whole expression = Units digit of 4*3*9*1 which is 8 .
Answer Choice D
Question: A discount electronics store normally sells all merchandise at a discount of 10 percent to 30 percent off the suggested retail price. If, during a special sale, an additional 20 percent were to be deducted from the discount price, what would be the lowest possible price of an item costing $300 before any discount?
A. $230.00
B. $145.60
C. $168.80
D. $182.00
Answer: C. $168.80
Explanation: Since the question is essentially just about multiplication, you can do the various mathstepsin a variety of ways (depending on whichever method you find easiest).
We're told that the first discount is 10% to 30%, inclusive. We're told that the next discount is 20% off of the DISCOUNTED price....
We're told to MAXIMIZE the discount (thus, 30% off the original price and then 20% off of the discounted price). Thatmathcan be written in a number of different ways (fractions, decimals, etc.):
30% off = (1 - .3) = (1 - 30/100) = (.7) and the same can be done with the 20% additional discount...
The final price of an item that originally cost $300 would be.....
($300)(.7)(.8) =
($300)(.56)=168
Final Answer:
C
Question: A man can row 9 kmph in still water. When the river is running at 1.2 kmph, it takes him 1 hour to row to a place and black. How far is the place?
A.4.32
B.4.42
C.4.52
D.4.62
Answer: B.4.42
Explanation: M = 9
S = 1.2
DS = 9 + 1.2 = 10.2
US = 9 - 1.2 = 7.8
x/10.2 + x/7.8 = 1
x = 4.42.Answer: B
Question: The area of a circle is increased by 300%. By what percent has the diameter of the circle increased?
A. 400%
B. 200%
C. 300%
D. 100%
Answer: D. 100%
Explanation: The area of the circle is increased by 300%, thus the area is increased 4 times.
The area of a circle it proportional to the square of the diameter (area=πd^2/4), therefore the diameter must increase 2 times (diameter increase 2 times = area increase 4 times), which is increase by 100%.
Answer: D.
Question: 95,70,54,45, ?
A.41
B.43
C.44
D.40
Answer: A.41
Explanation: 95 - 70 = 25 = 5^2
70 - 54 = 16 = 4^2
54 - 45 = 09 = 3^2
so we can write
45 - x = 04 = 2^2 , where x is the next number
x = 45 - 4 = 41
so the next number will be 41
ANSWER:A
Question: At present, the ratio between the ages of Arun and Deepak is 4:3. After 2 years, Arun's age will be 26 years. What is the age of Deepak at present?
A.16
B.17
C.10
D.18
Answer: D.18
Explanation: Let the present ages of Arun and Deepak be 4x and 3x years respectively.
Then, 4x + 2 = 26 => x = 8
Deepak's age = 3x = 18 years.
Answer: D
Question: A batch of widgets costs p + 5 dollars for a company to produce and each batch sells for p(6 – p) dollars. For which of the following values of p does the company make a profit?
A.3
B.4
C.5
D.6
Answer: A.3
Explanation: to make profit, selling price should be greater than cost price
p(6-p) - p-5 >0
=> p^2-5*p+5<0
hence p=3
A
Question: A professional athlete was offered a three-year contract to play with Team K that provided for an annual salary of $100,000 in the first year, an increase in annual salary of 20% over the previous year for the next two years, and a bonus of $75,000 on signing. Team L offered a three-year contract providing for an annual salary of $150,000 in the first year, an increase in annual salary of 10% over the previous year for the next two years, and no signing bonus. If he accepts the offer of Team L and fulfills the three-year contract terms, the athlete will receive how much more money by choosing Team L over Team K ?
A.$32,500
B.$57,500
C.$82,500
D.$92,000
Answer: B.$57,500
Explanation: Team K's contract = $100,000 + $100,000*1.2 + $100,000*1.2*1.2 + $75,000 = $439,000
Team L's contract = $150,000 + $150,000*1.1 + $150,000*1.1*1.1 = $496,500
The difference = $57,500.
Answer: B.
Question: The sum of four consecutive even integers is 1284. The greatest of them is:
A.324
B.342
C.364
D.382
Answer: A.324
Explanation: Sol.
Let the four integers be x, x + 2, x + 4 and x + 6
Then, x + (x + 2) + (x + 4) + (x + 6) = 1284 ⇔ 4x = 1272 ⇔ x = 318
∴ Greatest integer = x + 6 = 324.
Answer A
Question: The sum of the digits of a two-digit number is 12. The difference of the digits is 6. Find the number?
A.11
B.39
C.88
D.66
Answer: B.39
Explanation: Let the two-digit number be 10a + b
a + b = 12 --- (1)
If a>b, a - b = 6
If b>a, b - a = 6
If a - b = 6, adding it to equation (1), we get
2a = 18 => a =9
so b = 12 - a = 3
Number would be 93.
if b - a = 6, adding it to the equation (1), we get
2b = 18 => b = 9
a = 12 - b = 3.
Number would be 39.
There fore, Number would be 39 or 93.
Answer: B
Question: A bowl was filled with 10 ounces of water, and 0.0008 ounce of the water evaporated each day during a 50-day period. What percent of the original amount of water evaporated during this period?
A.0.004%
B.0.04%
C.0.40%
D.4%
Answer: C.0.40%
Explanation: Total amount of water evaporated each day during a 50-day period = .0008 * 50
=.0008 * 100/2
= .08/2
= .04
percent of the original amount of water evaporated during this period = (.04/10) * 100%
= 0.4 %
Answer C
Question: Find the middle one when The sum of three consecutive even numbers is 36?
A.10
B.12
C.15
D.17
Answer: B.12
Explanation: 3 consecutive numbers can be a - 1, a, a + 1
So sum of numbers = 3a = 36.
Hence a = 12.
B
Question: If the number 892,142,24x is divisible by 11, what must be the value of x?
A.1
B.2
C.3
D.0
Answer: D.0
Explanation: Multiplication rule of 11: (Sum of digits at odd places - Sum of digits at even places) should be divisible by 11
Given number: 892,142,24x
Sum of digits at odd places = 8 + 2 + 4 + 2 + x = 16 + x (i)
Sum of digits at even places = 9 + 1 + 2 + 4 = 16 (ii)
(i) - (ii) = 16 + x - 16 = x - 0
Hence x should be = 0 to make this a multiple of 11 (0) Option D
Question: When Professor Wang looked at the rosters for this term's classes, she saw that the roster for her economics class (E) had 24 names, the roster for her marketing class (M) had 28, and the roster for her statistics class (S) had 18. When she compared the rosters, she saw that E and M had 9 names in common, E and S had 7, and M and S had 10. She also saw that 4 names were on all 3 rosters. If the rosters for Professor Wang's 3 classes are combined with no student's name listed more than once, how many names will be on the combined roster?
A.30
B.34
C.42
D.48
Answer: D.48
Explanation: Total # of students 24+28+18-(9+7+10)+4=48.
Answer: D.
Question: Find a a prime number from the options below.
A.69
B.70
C.71
D.72
Answer: C.71
Explanation: Clearly, 71 is a prime number.
C
Question: A man goes from A to B at a speed of 20 kmph and comes back to A at a speed of 30 kmph. Find his average speed for the entire journey?
A.76 kmph
B.24 kmph
C.99 kmph
D.55 kmph
Answer: B.24 kmph
Explanation: Distance from A and B be 'd'
Average Speed = total distance/total time
Average Speed = (2d)/[(d/20) + (d/30)]
= (2d)/[5d/60) => 24 kmph.Answer:B
Question: What is the value of 11^x-11^(x+2), where x is the largest integer such that 11^x is a factor of 30,030?
A.-1331
B.-1320
C.-121
D.-120
Answer: B.-1320
Explanation: The given expression is 11x-11(x^+2) =11x(1-x)
1x needs to be factor of 30030 and x needs to be the largest integer possible. This means 11x needs to be the largest factor possible. The largest factor of a number is the number itself.
The largest factor of 30030 is 30030 = (11 * 2730)
x must be 2730
The value of 11x(1-x) = –1320.
ANSWER:B
Question: If a particular player is never chosen, in how many ways can 11 cricket players be chosen out of 16 players?
A.1245
B.1256
C.1365
D.1370
Answer: C.1365
Explanation: A particular players is never chosen, it means that 11 players are selected out of 15 players.
=> Required number of ways = 15C11 = 1365
C
Question: A 6-meter long wire is cut into two pieces. If the longer piece is then used to form a perimeter of a square, what is the probability that the area of the square will be more than 1 if the original wire was cut at an arbitrary point?
A.2/3
B.3/4
C.4/5
D.5/6
Answer: A.2/3
Explanation: The longer wire will form a square with an area more than 1 if the wire is cut at a point within two meters of either end. The probability of this is 4/6 = 2/3.
The answer is A.
Question: A train covers a distance of 12 km in 10 min. If it takes 6 sec to pass a telegraph post, then the length of the train is?
A.110 m
B.120 m
C.160 m
D.180 m
Answer: B.120 m
Explanation: Speed = (12/10 * 60) km/hr = (72 * 5/18) m/sec = 20 m/sec.
Length of the train = 20 * 6 = 120 m.
Answer: B
Question: A sells a bicycle to B at a profit of 30% and B sells it to C at a loss of 20%. Find the resultant profit or loss.
A.5%
B.4%
C.-4%
D.-12%
Answer: B.4%
Explanation: The resultant profit or loss = 30 - 20 - (30*20)/100 = 4%
profit = 4%
Answer is B
Question: If x, y, and z are negative integers and 3x - 3y = -3z, then which of the following statements must be true?
I. x > y
II. x > y > z
III. x = z
A.I and II
B.I only
C.II only
D.III only
Answer: B.I only
Explanation: If x, y, and z are negative integers and 3x - 3y = -3z, then which of the following statements must be true?
I. x > y
II. x > y > z
III. x = z
a. I and II
b. I only
c. II only
d. III only
e. None
From the question: we infer that x-y = -z
x,yz are negative integers .
ex: x= -4
y= -6
-4 - (-6) = -(-2). this implies x>y
here x is not equql to z (III)
z>y (II)
So (I) will be answer , SO option B)
Question: What is the value of the following expression?
(1/ (2^2 – 1)) + (1/ (4^2 – 1)) + (1/ (6^2 – 1)) + .... + (1/ (22^2 – 1))
A.a. 9/19
B.b. 10/19
C.c. 10/21
D.d. 11/23
Answer: D.d. 11/23
Explanation: it can be written into
1/3+1/15+ 1/35.....1/483
i.e
1/3+1/2*(1/3-1/5)+1/2*(1/5-1/7).... til last term - 1/2*(1/23)
all terms from 1/5 .. to second last term get cancelled
left with
1/3+1/6-1/46=1/2-1/46=22/46=11/23 D
Question: Kamal started a business investing Rs. 9000. After five months, Sameer joined with a capital of Rs. 8000. If at the end of the year, they earn a profit of Rs. 8610, then what will be the share of Sameer in the profit?
A.s.2323
B.s.2940
C.s.2329
D.s.2329
Answer: B.s.2940
Explanation: Kamal : Sameer = (9000 * 12) : (8000 * 7)
= 108:56 = 27:14
Sameer's share = 8610 * 14/41
= Rs.2940.
Answer: B
Question: In how many different number of ways 4 men and 2 women can sit on a shopa which can accommodate persons?
A.A)60
B.B)70
C.C)90
D.D)120
Answer: D.D)120
Explanation: 6p2 = 6 × 5 x 4 = 120
Option 'D'
Question: Twenty four men can do a work in 42 days. How many men are required to complete the work in 36 days?
A.20
B.28
C.50
D.40
Answer: B.28
Explanation: B
28
We have M1 D1 = M2 D2
So, 24 * 42 = M2 * 36 => M2 = 28.
Answer is B
Question: Find the value of x from (10)^2 x 7^3 Ã· 321 = x.
A.106.8
B.116.8
C.103.8
D.126.8
Answer: A.106.8
Explanation: Given Exp. =(10)^2 x 7^3 Ã· 321 = x
= 100 x 343Ã· 321
106.9
A
Question: There are 6 red shoes, 2 green shoes. If one draw randomly a shoe what is the probability of getting a red shoe
A.1/9
B.2/9
C.5/9
D.3/4
Answer: D.3/4
Explanation: total 8 from take one.
8c1=8
red 6 from one
6c1=6
6/8=3/4
ANSWER:D
Question: In 1 kg mixture of sand and iron, 20% is iron. How much sand should be added so that the proportion of iron becomes 10%?
A.1 kg
B.200gms
C.1.8kg
D.4.5kg
Answer: A.1 kg
Explanation: There are 200 grams of iron in 1 kg (1,000 grams) of the mixture.
If we add x grams of sand, the total amount would be 1,000 + x grams of mixture and we need 200 grams of iron to be 10% of that: 0.1(1,000 + x) = 200 --> x = 1,000.
Answer: A.
Or: for 200 grams of iron to be 10 of the mixture, the mixture must be 2,000 grams, thus 2,000 - 1,000 = 1,000 grams of sand should be added.
Answer: A.
Question: In an election between two candidates, one got 55% of the total valid votes, 20% of the votes were invalid. If the total number of votes was 8000, the number of valid votes that the other candidate got, was:
A.3500
B.3600
C.3270
D.3700
Answer: B.3600
Explanation: Number of valid votes = 80% of 8000 = 6400.
Valid votes polled by other candidate = 45% of 8000
=(45/100)X8000 =3600
ANSWER =B
Question: By selling 66 metres of cloth a man loses the selling price of 22 metres. Find the loss percent.
A.20%
B.25%
C.30%
D.35%
Answer: B.25%
Explanation: Loss = C.P. of 66 metres – S.P. of 66 metres
= S.P. of 22 metres
⇒ C.P. of 66 metres = S.P. of 88 metres
% loss = loss/C.P.of 66metres×100
= S.P.of22metres /C.P.of66metres×100
= S.P.of22metres /S.P.of88metres×100
= 22⁄88 × 100 = 25%
Answer B
* Try to solve by shortcut method
Question: Find the odd man out. 241, 263, 248, 271, 255, 277, 262
A.277
B.271
C.263
D.241
Answer: B.271
Explanation: Alternatively 22 is added and 15 is subtracted from the terms. Hence, 271 is wrong
241
241 + 22 = 263
263 - 15 = 248
248 + 22 = 270
270 - 15 = 255
255 + 22 = 277
277 - 15 = 262
Answer is B
Question: The food in a camp lasts for 25 men for 40 days. If ten more men join, how many days will the food last?
A.40 days
B.29 days
C.60 days
D.50 days
Answer: B.29 days
Explanation: one man can consume the same food in 25*40 = 1000 days.
10 more men join, the total number of men = 35
The number of days the food will last = 1000/35 = 29 days.
ANSWER:B
Question: A bag contains 12 red marbles. If someone were to remove 2 marbles from the bag, one at a time, and replace the first marble after it was removed, the probability that neither marble would be red is 9/16. How many marbles are in the bag?
A.48
B.24
C.60
D.72
Answer: A.48
Explanation: ok let me see if i can explain what went on in the previous post
lets say i have x marbles in the bag in total --> out of them 12 are red
so the probability of pulling a non-red marble is (x -12) / x
now the marble is placed back in the bag and we have x marbles again, of which again 12 are red. so the probability of pulling a non-red marble out is (x-12) / x
probability theorm states that if the probability of event A occuring is m and the probability of event B occuring is n then the probability of both A and B occuring is m*n
so therefore the probability of 2 non-red marbles getting pulled out is [(x-12)/x ] * [(x-12)/x]
this is given as 9/16
-->(x-12)^2= 16/25
x^2
A
square rooting u have x-12/x = 3/4 or 4x-48 =3x or x = 48
Question: A local restaurant recently renovated its dining space, purchasing new tables and chairs to use in addition to the original tables and chairs. The new tables each seat six customers, while the original tables each seat four customers. Altogether, the restaurant now has 40 tables and is capable of seating 220 customers. How many more new tables than original tables does the restaurant have?
A.10
B.20
C.30
D.34
Answer: B.20
Explanation: X = Number of original tables
Y = Number of new tables
Capacity of original tables = 4
Capacity of new tables = 6
Total number of tables = X + Y = 40.....(1)
Total capacity = 4X + 6Y = 220.......(2)
(2) - 4*(1) --> 2Y = 60 --> Y = 30, X = 10
How many more new tables than original tables does the restaurant have? --> Y - X = 30 - 10 = 20
Answer: B
Question: A train 400 m long can cross an electric pole in 20 sec and then find the speed of the train?
A.72
B.70
C.60
D.85
Answer: A.72
Explanation: Length = speed*time
S=400/20
s=20 m/sec
Speed = 20*18/5
speed = 72 kmph
ANSWER A
Question: Three candidates contested an election and received 1136, 7636 and 11628 votes respectively. What percentage of the total votes did the winning candidate get?
A.57%
B.50%
C.52%
D.60%
Answer: A.57%
Explanation: Explanation :
Votes received by the winning candidate = 11628
Total votes = 1136 + 7636 + 11628 = 20400
Required percentage = (11628/20400) × 100 = 11628/204 = 2907/51 = 969/17 = 57%
Answer : Option A
Question: If a: b = 10: 9, b: c = 17: 12, find a: b: c?
A.150: 143: 118
B.160: 173: 128
C.170: 153: 108
D.180: 163: 138
Answer: C.170: 153: 108
Explanation: a: b = 10: 9
b: c = 17: 12
a: b: c = 170: 153: 108
ANSWER:C
Question: Two cars start from the opposite places of a main road, 150 km apart. First car runs for 25 km and takes a right turn and then runs 15 km. It then turns left and then runs for another 25 km and then takes the direction back to reach the main road. In the mean time, due to minor break down the other car has run only 35 km along the main road. What would be the distance between two cars at this point?
A.65 km
B.75 km
C.80 km
D.85 km
Answer: A.65 km
Explanation: 150-((25+25)+35)
ANSWER:A
Question: A hiker walked for 3 days. She walked 25 miles on the first day, walking 5 miles per hour. On the second day she walked for one less hour but she walked one mile per hour, faster than on the first day. On the third day she walked the same number of hours as on the first day, but at the same speed as on the second day. How many miles in total did she walk?
A.24
B.79
C.58
D.60
Answer: B.79
Explanation: She walked 25 miles on the first day, walking 5 miles per hour i.e. total time of walk on Day-1 = 25/5 = 5 Hours
Second day time of walk = 5-1 = 4 hours and Speed = 5+1=6 miles per hour i.e. Distance walked on second day = 4*6 = 24 miles
Third day time of walk = 5 hours and Speed = 6 miles per hour i.e. Distance walked on second day = 5*6 = 30 miles
Total Distance travelled on three days = 25+24+30 = 79
Answer: Option 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.225 cm2
B.275 cm2
C.285 cm2
D.315 cm2
Answer: C.285 cm2
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: A train running at the speed of 60 km/hr crosses a pole in 18 seconds. Find the length of the train?
A.150 meter
B.876 meter
C.300 meter
D.719 meter
Answer: C.300 meter
Explanation: Speed = 60*(5/18) m/sec = 50/3 m/sec
Length of Train (Distance) = Speed * Time
(50/3) * 18
= 300 meter
Answer: C
Question: 138.009 + 341.981 – 146.305 = 123.6 + ?
A.120.085
B.120.85
C.220.085
D.None of these
Answer: D.None of these
Explanation: Solution
Let 138.009 + 341.981 - 146.305 = 123.6 + x.
Then, x = (138.009 + 341.981) - (146.305 + 123.6) = 479.99 - 269.905 = 210.085 . Answer D
Question: My grandson is about as many days as my son in weeks, and my grandson is as many months as I am in years. My grandson, my son and I together are 120 years. Can you tell me my age in years ?
A.65
B.72
C.44
D.73
Answer: B.72
Explanation: B
I am 72 years old.
Let m be my age in years. If s is my son's age in years, then my son is 52s weeks old. If g is my grandson's age in years, then my grandson is 365g days old. Thus,
365g = 52s.
Since my grandson is 12g months old,
12g = m.
Since my grandson, my son and I together are 120 years,
g + s + m = 120.
The above system of 3 equations in 3 unknowns (g, s and m) can be solved as follows.
m / 12 + 365 m / (52 x 12) + m = 120 or
52 m + 365 m + 624 m = 624 x 120 or
m = 624 x 120 / 1041 = 72.
So, I am 72 years old.
Question: The average age of the mother and her six children is 12 years which is reduced by 5 years if the age of the mother is excluded. How old is the mother?
A.40 years
B.42 years
C.48 years
D.50 years
Answer: B.42 years
Explanation: Sol.
Therefore age of the mother
= ( 12 × 7 – 7 × 6)
= 42 years.
Answer B