RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: The length of a rectangle is increased to 2 times its original size and its width is increased to 3 times its original size. If the area of the new rectangle is equal to 1800 square meters, what is the area of the original rectangle?
A.100 square meters
B.200 square meters
C.300 square meters
D.400 square meters
Answer: C.300 square meters
Explanation: If L and W be the original length and width of the rectangle and its area is given by
L ? W
After increase the length becomes 2 L and the width becomes 3 W. The area is then given by (2 L) ? (3 W) and is known. Hence
(2 L) ? (3 W) = 1800
Solve the above equation to find L ? W
6 L ? W = 1800
L ? W = 1800 / 6 = 300 square meters , area of original rectangle
correct answer C
Question: A man invests some money partly in 12% stock at 132 and partly in 10% stock at 80.To obtain equal dividends from both,he must invest the money in the ratio :
A.3 : 4
B.3 : 5
C.11:8
D.16 : 15
Answer: C.11:8
Explanation: Solution
For an income of Rs. 1 in 12% stock at 132, investment = Rs. (132/12)= Rs. 11 .
For an income of Rs. 1 in 10% stock at 80, investment = Rs.(80/10) = Rs. 8.
∴ Ratio of investments = 11:8 =11:8
Answer C
Question: .008/?= .01
A..8
B..09
C..009
D..0009
Answer: A..8
Explanation: Let .008/x = .01;
Then x = .008/.01
= .8/1
= .8
Answer is A
Question: I. a3 - 988 = 343,
II. b2 - 72 = 49 to solve both the equations to find the values of a and b?
A.a > b
B.a ≥ b
C.a < b
D.a ≤ b
Answer: B.a ≥ b
Explanation: Explanation:
a3 = 1331 => a = 11
b2 = 121 => b = ± 11
a ≥ b
B)
Question: Tanks Q and B are each in the shape of a right circular cylinder. The interior of tank Q has a height of 10 meters and a circumference of 8 meters, and the interior of tank B has a height of 8 meters and a circumference of 10 meters. The capacity of tank Q is what percent of the capacity of tank B?
A.75%
B.80%
C.100%
D.120%
Answer: B.80%
Explanation: B.
For Q, r=8/2pi. Its capacity = (4pi)^2 * 10= 160pi
For B, r=10/pi. Its capacity = (5pi)^2 *8 = 200pi
Q/B = 160pi/200pi = 0.8
Question: 4 dice are thrown simultaneously on the board. Find the probability show the same face.
A.1/115
B.2/113
C.1/216
D.2/121
Answer: C.1/216
Explanation: The total number of elementary events associated to the random experiments of throwing four dice simultaneously is:
=6×6×6×6=64=6×6×6×6=64
n(S)=64n(S)=64
Let XX be the event that all dice show the same face.
X={(1,1,1,1,),(2,2,2,2),(3,3,3,3),(4,4,4,4),(5,5,5,5),(6,6,6,6)}X={(1,1,1,1,),(2,2,2,2),(3,3,3,3),(4,4,4,4),(5,5,5,5),(6,6,6,6)}
n(X)=6n(X)=6
Hence required probability,
=n(X)n(S)=664=n(X)n(S)=664
=1/216
C
Question: 10 men, working 4 hours a day can complete a work in 18 days. How many hours a day must 15 men work to complete the work in 12 days ?
A.4 hours a day
B.5 hours a day
C.6 hours a day
D.7 hours a day
Answer: A.4 hours a day
Explanation: Explanation:
More Men, Less Hours {Indirect Proportion}
Less Days, More Hours {Indirect Proportion}
[men 15 10
days 12 18] ::4:x
=>xâˆ—15âˆ—12=10âˆ—18âˆ—4
=>x=10âˆ—18âˆ—4/ 15âˆ—12
=>x=4
Option A
Question: If (x + 10)^2 = 144, which of the following could be the value of 2x?
A.–26
B.–22
C.–44
D.66
Answer: C.–44
Explanation: You can also get to the answer by backsolving using answer choices
Starting with x= -22
(x + 10)^2 = 144
(-22 + 10)^2 = 144 =====> (-12)^2 = 144 Bingo, Clearly, among the answer choices only -22 will result in 144 in the equation so x must be -22,
Then 2x = 2 * -22 = -44
Answer: C
Question: What percent is 6 gm of 1 kg?
A.0.06%
B.0.6%
C.0.006%
D.6%
Answer: B.0.6%
Explanation: Explanation:
1 kg = 1000 gm
6/1000 * 100 = 600/1000
=3/5 = 0.6 %
Answer: Option B
Question: Ten years ago A was half of B in age. If the ratio of their present ages is 3 : 4, what will be the total of their present ages
A.30
B.35
C.37
D.41
Answer: B.35
Explanation: Explanation:
Let A's age 10 years ago = x years.
Then, B's age 10 years ago = 2x years.
(x + 10) / (2x+ lO) = 3/4
=> x = 5.
So, the total of their present ages =(x + 10 + 2x + 10)
= (3x + 20) = 35 years
Option B
Question: The least number, which when divided by 12, 15, 20 and 54 leaves in each case a remainder of 5 is:
A.545
B.488
C.542
D.548
Answer: A.545
Explanation: Required number = (L.C.M. of 12, 15, 20, 54) + 5
= 540 + 5
= 545.
answer :A
Question: A can do a piece of work in 12 days. He worked for 15 days and then B completed the remaining work in 10 days. Both of them together will finish it in.
A.12 1/2 days
B.12 1/9 days
C.12 8/2 days
D.17 1/2 days
Answer: A.12 1/2 days
Explanation: 15/25 + 10/x = 1 => x = 25
1/25 + 1/25 = 2/25
25/2 = 12 1/2 days
Answer: A
Question: The average age of students of a class is 15.8 years. The average age of boys in the class is 16.4 years and that of the girls is 15.4 years. The ration of the number of boys to the number of girls in the class is?
A.2:6
B.2:3
C.2:5
D.2:1
Answer: B.2:3
Explanation: Let the ratio be k : 1. Then,
k * 16.4 + 1 * 15.4 = (k + 1) * 15.8
= (16.4 - 15.8)k = (15.8 - 15.4)
= k = 0.4/0.6 = 2/3
Required ratio = 2/3 : 1 = 2:3.
Answer:B
Question: If 7875 / 5.25 = 1500, then 787.5 / 52.5 is equal to ?
A.15
B.19
C.12
D.14
Answer: A.15
Explanation: Answer
Given expression 787.5 / 52.5 = 7875 / 525
= 7875 / (525 x 100)
= 1500 / 100
15
Correct Option: A
Question: The ratio of number of boys and girls in a school is 2:5. If there are 490 students in the school, find the number of girls in the school?
A.150
B.350
C.300
D.370
Answer: B.350
Explanation: Let the number of boys and girls be 2x and 5x
Total students = 490
Number of girls in the school = 5*490/7 = 350
Answer is B
Question: A train moves 100m in 2 sec and then find the speed travelled?
A.28
B.900
C.50
D.180
Answer: D.180
Explanation: Length = Speed * time
Speed = L/T
S = 100m/2sec
S = 50 M/Sec
Speed= 50*18/5 (To convert M/Sec in to Kmph multiply by 18/5)
Speed = 180Kmph.Answer:D
Question: A selection committee is to be chosen consisting of 5 ex-technicians. Now there are 12 representatives from four zones. It has further been decided that if Mr. X is selected, Y and Z will not be selected and vice-versa. In how many ways it can be done?
A.572
B.672
C.472
D.372
Answer: B.672
Explanation: Solution:
10C5: when both are not included.
10C4: when one of them is included.
Number of ways = 10C5 +10C4+ 10C4 = 672
Answer: Option B
Question: 7 men and 2 boys working together can do four times as much work as a man and a boy. Working capacity of man and boy is in the ratio
A.1:2
B.1:3
C.2:1
D.2:3
Answer: D.2:3
Explanation: Explanation:
Let 1 man 1 day work = x
1 boy 1 day work = y
then 7x + 2y = 4(x+y)
=> 3x = 2y
=> x/y = 2/3
=> x:y = 2:3
Option D
Question: A box contains 3 blue marbles, 4 red, 6 green marbles and 2 yellow marbles. If four marbles are picked at random, what is the probability that none is blue?
A.33/16
B.33/91
C.33/29
D.33/18
Answer: B.33/91
Explanation: Given that there are three blue marbles, four red marbles, six green marbles and two yellow marbles. When four marbles are picked at random, then the probability that none is blue is
= ¹²C₄/¹⁵C₄
= (12 * 11 * 10 * 9)/(15 * 14 * 13 * 12)
= 33/91
Answer: B
Question: The radii of two cones are in ratio 2:1, their volumes are equal. Find the ratio of their heights.
A.1:4
B.1:3
C.1:2
D.1:5
Answer: A.1:4
Explanation: Explanation:
Let their radii be 2x, x and their heights be h and H resp.
Then,
Volume of cone =1/3πr2h
1/3∗π∗(2x)2∗h /1/3∗π∗x2∗H
=>hH=14
=>h:H=1:4
Option A
Question: A sum of Rs.312 was divided among 100 boys and girls in such a way that the boy gets Rs.3.60 and each girl Rs. 2.40 the number of girls is
A.35
B.40
C.45
D.50
Answer: B.40
Explanation: Explanation:
Step (i): Let x be the number of boys and y be the number of girls.
Given total number of boys and girls = 100
x+y=100 -------------- (i)
Step (ii): A boy gets Rs. 3.60 and a girl gets Rs. 2.40
The amount given to 100 boys and girls = Rs. 312
3.60x + 2.40y = 312 -------------- (ii)
Step (iii):
Solving (i) and (ii)
3.60x + 3.60y = 360 --------- Multiply (i) by 3.60
3.60x + 2.40y = 312 --------- (ii)
1.20y = 48
y = 48 / 1.20
= 40
Number of girls = 40
Answer: B
Question: A and B together can do a piece of work in 6 days and A alone can do it in 13 days. In how many days can B alone can do it?
A.12 days
B.15 days
C.78/7 days
D.21 days
Answer: C.78/7 days
Explanation: Explanation:
A and B can do work 1/6 in 1 day
A alone can do 1/13 work in 1 day
B alone can do (1/6 -1/13) =7/78 work in 1 day
=> complete work can be done in 78/7 days by B
Answer: Option C
Question: From a Group of 8 People, Including Gary and Nina, 3 people are to be selected at random to work on a certain project. What is the probability that 3 people selected will include Gary but not Nina
A.5/56
B.9/56
C.15/56
D.21/56
Answer: C.15/56
Explanation: Number of ways of selecting 3 people out of 8 people = 8C3
In the three members Gary will always be there in the team. At this step we have vacancy for 2 more members and 7 members are available. Nina cannot be there in the team. So 2 members have to be selected and the number of available members = 7 - Nina = 6
Number of ways to form a 3 member team that includes Gary and excludes Nina = 6C2
Probability = 6C2/8C3 = 15/56
Answer: C
Question: A family consisting of one mother, one father, two daughters and a son is taking a road trip in a sedan. The sedan has two front seats and three back seats. If one of the parents must drive and the two daughters refuse to sit next to each other, how many possible seating arrangements are there?
A.28
B.32
C.48
D.60
Answer: B.32
Explanation: Sisters can sit separately in two ways:
1. one of them is on the front seat (2 ways). Others (including second sister) can be arranged in: 2 (drivers seat)*3! (arrangements of three on the back seat)=12 ways. Total for this case: 2*12=24
Or
2. both by the window on the back seat (2 ways). Others can be arranged in: 2 (drivers seat)*2 (front seat)*1(one left to sit between the sisters on the back seat)=4 ways. Total for this case: 2*4=8.
Total=24+8=32. ANS:B
Question: How many bricks each measuring 20cm x 10cm x 8cm, will be needed to build a wall 10m x 8m x 24.5m
A.12250
B.13400
C.12500
D.14340
Answer: A.12250
Explanation: Explanation:
no. of bricks= volume of the wall/volume of 1 brick = (1000 x 800 x 24.5) / (20 x 10 x 8) = 12250
Answer: A
Question: Each day a man meets his wife at the train station after work, and then she drives him home. She always arrives exactly on time to pick him up. One day he catches an earlier train and arrives at the station an hour early. He immediately begins walking home along the same route the wife drives. Eventually his wife sees him on her way to the station and drives him the rest of the way home. When they arrive home the man notices that they arrived 30 minutes earlier than usual. How much time did the man spend walking?
A.45 minutes
B.50 minutes
C.40 minutes
D.55 minutes
Answer: A.45 minutes
Explanation: As they arrived 30 minutes earlier than usual, they saved 30 minutes on round trip from home to station (home-station-home) --> 15 minutes in each direction (home-station) --> wife meets husband 15 minutes earlier the usual meeting time --> husband arrived an hour earlier the usual meeting time, so he must have spent waking the rest of the time before their meeting, which is hour-15 minutes= 45 minutes.
Answer: A
Question: How much time will a train of length 200 m moving at a speed of 72 kmph take to cross another train of length 300 m, moving at 36 kmph in the same direction?
A.sec
B.sec
C.sec
D.sec
Answer: A.sec
Explanation: The distance to be covered = Sum of their lengths = 200 + 300 = 500 m.
Relative speed = 72 -36 = 36 kmph = 36 * 5/18 = 10 mps.
Time required = d/s = 500/10 = 50 sec.
Answer: A
Question: How many bricks, each measuring 25 cm x 11.25 cm x 6 cm, will be needed to build a wall of 8 m x 6 m x 22.5 cm?
A.5600
B.6000
C.6400
D.7200
Answer: C.6400
Explanation: Number of bricks =Volume of the wall/Volume of 1 brick =	(800 x 600 x 22.5)/(25 x 11.25 x 6) = 6400.
Answer: Option C
Question: A can do a work in 14 days. B is 40% more efficient than A. How many days does B alone take to do the same job?
A.9
B.10
C.11
D.12
Answer: B.10
Explanation: Ratio of times taken by A and B = 140:100 = 7:5
suppose B alone to take x days to do the work
then, 7:5::14:x
7x= 5*14
x=10 days
correct option is B
Question: Each light bulb at a hotel is either incandescent or fluorescent. At a certain moment, forty percent of the incandescent bulbs are switched on, and eighty percent of the fluorescent bulbs are switched on. If 72 percent of all the bulbs are switched on at this moment, what percent of the bulbs that are switched on are incandescent?
A.24%
B.16%
C.11%
D.7%
Answer: C.11%
Explanation: Let I be the number of incandescent bulbs.
Let F be the number of fluorescent bulbs.
0.4I + 0.8F = 0.72(I+F)
0.08F = 0.32I
F = 4I
This means that for every 1 incandescent bulb, there are 4 fluorescent bulbs.
The percent of bulbs that are switched on which are incandescent is:
0.4I / (0.4I + 0.8F) = 0.4I / (0.4I + 0.8*4I) = 0.4I / 3.6I = 1/9 which is about 11%.
The answer is C.
Question: If -1 < x < 1, which of the following must be true?
I. x^3 < x^2
II. x^5 < 1 – x
III. x^4 < x^2
A.I only
B.I and II only
C.II and III only
D.I and III only
Answer: D.I and III only
Explanation: I. x^3 < x^2 --> from -1 < x < 1 x must be a decimal so multiplying it by itself makes it a smaller value positive or negative. x^2 is always positive so x^3 being a small value always makes x^3<x^2 so this statement is true.
II. x^5 < 1 – x --> x(x^4+1) < 1 --> since 1(1+1)=2 > 1, so this statement is false.
III. x^4 < x^2 --> reduce by x^2 (we can safely do that since from -1 < x < 1 is follows that x^2>0): x^2 < 1. Again, as -1 < x < 1, then x^2 must be less than 1. Hence, this statement is also true.
Answer: D.
Question: Lucy deposited $67600 in an investment fund that provided 16 percent annual return compounded quarterly. If she made no other transactions with the fund, in how much time, in months, did her investment earn a total interest of $5300?
A.90.5
B.92
C.93
D.90
Answer: D.90
Explanation: A = P + I = 67600 + 5300 = 72900
72900 = 67600(1 + 8/4*100)^(4t)
(729/676) = (102/100)^(4t)
t =7 1/2 yrs = 90 months
Answer: D
Question: The number 95 can be written as the sum of the squares of 4 different positive integers in two ways. Of the following, which can be the sum of these 4 integers?
A.9
B.10
C.15
D.18
Answer: C.15
Explanation: The only possible sum for 4 different squares of an integer with total sum number is 95 are :
49 + 36 + 9 + 1 = 95 which are the square from numbers : 7, 6, 3, 1 (total sum number is 17)
or
81 + 9 + 4 + 1 = 95 which are the square from numbers : 9, 3, 2, 1 (total sum number is 15)
hence the answer is (C)
Question: This is an ancient problem dating back to about 310 A.D.
Demochares had lived one-fourth of his life as a boy, one-fifth as a young, one-third as a man. and has spent thirteen years in his dotage. How old is Demochares?
A.44
B.53
C.75
D.60
Answer: D.60
Explanation: D
60
Demochares must be sixty years of age.
Question: A book is bought for Rs.600/- and sold at a profit of 10% find its selling price?
A.s.740/-
B.s.660/-
C.s.680/-
D.s.720/-
Answer: B.s.660/-
Explanation: 100 % ------> 600 (100 * 6 = 600)
110 % ------> 660 (110 * 6 = 660)
Selling price = Rs.660/-
Option 'B'
Question: A cistern can be filled by a tap in 4 hours while it can be emptied by another tap in 9 hours. If both the taps are opened simultaneously, then after how much time will the cistern get filled?
A.5.2 hrs
B.2.9 hrs
C.1.9 hrs
D.7.2 hrs
Answer: D.7.2 hrs
Explanation: Net part filled in 1 hour = (1/4 - 1/9) = 5/36
The cistern will be filled in 36/5 hrs i.e., 7.2 hrs.
Answer:D
Question: If P(32, 6) = kC (32, 6), then what is the value of k?
A.6
B.32
C.120
D.720
Answer: D.720
Explanation: Since 32P6 = k32C6
⇒ 32/ ( 32-6 ) = k(32/ ( 32-6 )
⇒k = 6! = 720
Answer D
Question: In what time will a train 200 meters long cross an electric pole, if its speed is 128 km/hr
A.5 seconds
B.5.7 seconds
C.3 seconds
D.2.5 seconds
Answer: B.5.7 seconds
Explanation: Explanation:
First convert speed into m/sec
Speed = 128*(5/18) = 35 m/sec
Time = Distance/speed
= 200/35 = 5.7 seconds
Option B
Question: Two trains are moving in the same direction at 72 kmph and 36 kmph. The faster train crosses a man in the slower train in 27 seconds. Find the length of the faster train?
A.270
B.287
C.269
D.200
Answer: A.270
Explanation: Relative speed = (72 - 36) * 5/18 = 2 * 5 = 10 mps.
Distance covered in 27 sec = 27 * 10 = 270 m.
The length of the faster train = 270 m.
Answer: A
Question: The area of a parallelogram is 243sq m and its altitude is three times the corresponding base. What is the length of the base?
A.4
B.9
C.10
D.4
Answer: B.9
Explanation: 3x * x = 243 => x
= 9
Answer: B
Question: There are 8 disks in a container that are numbered 23, 24, 25, 26, 28, 29, 30 and 31. 4 disks are randomly removed from the container, one after the other, without replacement. Then a list of 5 numbers containing the 4 numbers on the disks selected, together with the number 27 will be made. What is the probability that 27 is the median of the list of 5 numbers?
A.2/5
B.17/35
C.1/2
D.18/35
Answer: D.18/35
Explanation: we must consider that there are two ways to choose from A or B, and then two ways to choose each number from their respective groups:
Group A (23,24,25,26) and Group B (28,39,30,31). Then we saw that in order to have a median of 27 we need to have 2 from group and and 2 from group B.
The probability of that is 4/8 x 3/7 x 4/6 x 3/5 x (1/2) x (1/2) = 18/35.
Answer: D.
Question: Which of the following is closest to 1/6+1/66+1/666
A.1/4.5
B.1/7
C.1/5.67
D.1/9
Answer: C.1/5.67
Explanation: 1/6+1/66+1/666=0.16+0.015+0.0015=0.1765=1/5.665
Answer C
Question: Bill made a profit of 10% by selling a product. If he had purchased that product for 10% less and sold it at a profit of 30%, he would have received $ 35 more. What was his original selling price?
A. $770
B. $550
C. $700
D. $1100
Answer: B. $550
Explanation: Let the original purchase price be X
So original selling price at 10% profit = 1.1X
If product is purchased at 10% less of original = 0.9X
Profit of 30% on this price = 1.3(0.9X)
He would have received $35 more in second scenario => 1.3(0.9X) - 1.1X = 35
=> 0.07X = 35
=> X = $500
Original purchase price = $500
Hence, original selling price (at 10% of profit) = 1.1(500) = $550
Option B
Question: If 5% more is gained by selling an article for Rs. 350 than by selling it for Rs. 340, the cost of the article is?
A.127
B.688
C.200
D.121
Answer: C.200
Explanation: Let C.P. be Rs. x.
Then, 5% of x = 350 - 340 = 10
x/20 = 10 => x = 200
Answer: C
Question: Mangala completes a piece of work in 10 days, Raju completes the same work in 20 days. If both of them work together, then the number of days required to complete the work is?
A.8 days
B.10 days
C.20/3 days
D.14 days
Answer: C.20/3 days
Explanation: If A can complete a work in x days and B can complete the same work in y days, then, both
of them together can complete the work in x y/ x+ y days.
That is, the required No. of days = 10 Ã— 20/30 = 20/3 days
C)
Question: Three cannons are firing at a target. If their individual probabilities to hit the target are 0.4, 0.2, and 0.3 respectively, what is the probability that none of the cannons will hit the target after one round of fire?
prob. that all the cannons will hit the target = .06
prob. that none of the cannons will hit = 1 - .06 = .94
A.0.06
B.0.336
C.0.21
D.0.29
Answer: B.0.336
Explanation: The probability that eachdoesn'thit is: 0.4, 0.2, and 0.3. When we have multiple independent events, we multiply the probabilities:
.6*.8*.7 = 0.336.
Option: B
Question: The average weight of three boys P, Q and R is 54 kg, while the average weight of three boys Q, S and T is 60 kg. What is the average weight of P, Q, R, S and T?
A.338
B.279
C.279
D.342
Answer: D.342
Explanation: Explanation:
Total weight of (P + Q + R) = {54*3} kg = 162 kg
Total weight of(Q + S + T) = (60 *3) kg = 180 kg
Adding both, we get : P + 2Q + S + R + T = (162 + 180) kg = 342 kg
So, to find the average weight of P, Q, R, S & T, we ought to know Q's weight, which is not given.
The data is inadequate.
ANSWER:D
Question: The length of a rectangular plot is 20 mtr more than its breadth. If the cost of fencingthe plot at 26.50 per meter is Rs. 5300, what is the length of the plot in mtr?
A.50 m
B.60 m
C.65 m
D.75 m
Answer: B.60 m
Explanation: Let breadth = x metres.
Then, length = (x + 20) metres.
Perimeter = 5300 m = 200 m.
26.50
2[(x + 20) + x] = 200
2x + 20 = 100
2x = 80
x = 40.
Hence, length = x + 20 = 60 m
B
Question: Tough and Tricky questions: Exponents.
If a and b are positive integers and x = 5^a and y = 7^b, which of the following is a possible units digit of xy?
A.1
B.4
C.5
D.7
Answer: C.5
Explanation: Only Units digit of X and Y contribute to the Units digit of XY.
Finding all values ofXfor positive values ofa
When,
a=1; X=5
a=2; X=25
a=3; X=125........ Units digit repeat in a cycle of 5......
Similarly, Finding all values ofYfor positive values ofb
When,
b=1; Y=7
b=2; Y= 49
b=3; Y= 343
b=4; Y=2041
b=5; Y=16807....... Units digit repeat in cycle of 7,9,3,1,7,9,3....
So, possible value of Units digit of XY can be found by considering all possibilities of Units digit of X and Y
When X=5 and Y=7: Units digit of XY = 35
When X=5 and Y=9: Units digit of XY = 45
When X=5 and Y=3: Units digit of XY = 15
When X=5 and Y=1: Units digit of XY = 5
Only one possibilities for Units digit of XY i.e. 5
therefore answer is C
Question: There is a road beside a river.Two friends started from a place A, moved to a temple situated at another place B and then returned to A again. One of them moves on a cycle at a speed of 12 km/hr, while the other sails on a boat at a speed of 10 km/hr. If the river flows at the speed of 4 km/hr, which of the two friends will return to place A first ?
A.5.4 km /hr
B.7.2 km /hr
C.8.4 km/hr
D.9.6 km /hr
Answer: C.8.4 km/hr
Explanation: speed of cycle both side on road will be same
average speed of cycle = 12 kmhr
downstream , boat speed =10+4= 14kmhr
upstream = 10- 4 = 6kmhr
averge of boat speeds =( 2* 14* 6)/14+6=8.4 kmhr
ANSWER:C
Question: A goods train runs at the speed of 72 km/hr and crosses a 250 m long platform in 26 sec. What is the length of the goods train?
A.187 m
B.278 m
C.279 m
D.270 m
Answer: D.270 m
Explanation: Speed = 72 * 5/18 = 20 m/sec.
Time = 26 sec.
Let the length of the train be x meters.
Then, (x + 250)/26 = 20
x = 270 m.
Answer: D
Question: Find the odd man out. 1050, 510, 242, 106, 46, 16, 3
A.46
B.106
C.510
D.1050
Answer: B.106
Explanation: Explanation :
1050
(1050 - 30)/2 = 510
(510 - 26)/2 = 242
(242 - 22)/2 = 110
(110 - 18)/2 = 46
(46- 14)/2 = 16
(16- 10)/2 = 3
Hence, 110 should have come in place of 106
Answer : Option B
Question: If the area of circle is 616 sq cm then its circumference?
A.11
B.88
C.99
D.266
Answer: B.88
Explanation: 22/7 r2 = 616 => r = 14
2 * 22/7 * 14 = 88 Answer: B
Question: ((1^(m+1))/(5^(m+1)))((1^18)/(4^18)) = 1/(2(10)^35)
What is m?
A.17
B.18
C.34
D.35
Answer: C.34
Explanation: ((1^(m+1))/(5^(m+1)))((1^18)/(4^18)) = 1/(2(10)^35)
((1/5)^(m+1) ) * ((1/2)^36) = 1/ (2 * (2*5)^35))
2^36 will cancel out,since 1 can be written as 1^35 ,So (1/5)^(m+1)= (1/5)^35
((1/5)^(m+1) ) * ((1/2)^36) = 1/[(2^36)*(5^35)]
So, m=34
Answer C
Question: Average age of boys in a class is 16 years and average age of girls is 15 years, what is the average age
of all
A.15.5
B.15
C.16
D.Cant be computed
Answer: D.Cant be computed
Explanation: Explanation:
As number of girls and boys is not given so result cant be computed
Answer: Option D
Question: Find the simple interest on Rs.567 for 7 months at 9 paisa per month?
A.s.357.21
B.s.322.12
C.s.400
D.s.278.9
Answer: A.s.357.21
Explanation: Explanation:
I = (567*7*9)/100 = 357.21
Answer: Option A
Question: Look at this series: 97, 97, 93, 93, 89, 89, 85, 85, ... What number should come next?
A.75
B.76
C.78
D.81
Answer: D.81
Explanation: Explanation:
In this series, each number is repeated, then 4 is subtracted to arrive at the next number.
Answer: Option D