RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: The H.C.F. of two numbers is 11 and their L.C.M. is 7700. If one of the numbers is 275, then the other is:
A.306
B.308
C.310
D.311
Answer: B.308
Explanation: LCM X HCF = First No. X Second No.
LCM=7700
HCF=11
First No.=275
7700 X 11 = 275 X Second No.
Second No.= 308
answer :B
Question: An urn contains 10 black and 5 white balls. Two balls are drawn from the urn one after the other
without replacement. What is the probability that both drawn balls are black?
A.1/5
B.2/7
C.3/7
D.4/5
Answer: C.3/7
Explanation: Let E and F denote respectively the events that first and second ball drawn
are black. We have to find P(E n F) or P (EF).
Now P(E) = P (black ball in first draw) = 10/15
Also given that the first ball drawn is black, i.e., event E has occurred, now there are 9 black balls and five white balls left in the urn. Therefore, the probability that the second ball drawn is black, given that the ball in the first draw is black, is nothing but the conditional probability of F given that E has occurred.
That is P(F|E) = 9/14
By multiplication rule of probability, we have
P (E n F) = P(E) P(F|E)
= 10/15 × 9/14 = 3/7
C
Question: The simple interest on Rs.12000 at a certain rate of interest in five years is Rs.7200. Find the compound interest on the same amount for five years at the same rate of interest.
A.Rs.3502.80
B.Rs.3052.40
C.Rs.3054.8
D.Rs.3052.80
Answer: D.Rs.3052.80
Explanation: R = 100 I / PT
=> R = (100 * 7200)/ (12000 * 5) = 12%
CI = P{ [1 + R /100]n - 1}
= 12000 { [ 1 + 12 / 100]2 - 1} = Rs.3052.80
ANSWER:D
Question: a, b, c, and d are positive consecutive even integers and a < b < c < d.
If the product of the highest and lowest numbers is six more than the sum of the middle numbers, what is the product of the smallest two numbers?
A.2
B.4
C.8
D.12
Answer: C.8
Explanation: We know the numbers must be consecutive even numbers, from the list 2, 4, 6, 8, 10, 12, 14, 16, and so on.
The product ad is 6 more than the sum bc. By testing some possible ad products (even numbers separated by two other even numbers), we can quickly see that the numbers have to be quite small: 6x12 is 72, much higher than any of the possible sums, and the products will go up much faster than the sums will.
However, the lowest possible sequence gives an ad product of 2x8, or 16. And summing the middle numbers gives 10, exactly six less than the product. We have found the sequence: 2-4-6-8.
The answer, then, is the product of the smallest two numbers, or 2x4, which is 8 (option C).
Question: A radio station has to choose a week of the four in a month to broadcast a certain program, and that set will repeat each month. The program can be broadcast equally on any of the four week —- 1st week vs. last week don’t matter at all —- nor does it matter whether the week the program airs are adjacent or not. Absolutely any week of the 4 weeks can be chosen. How many different week combinations of the 4 weeks can be constructed?
A.4
B.15
C.21
D.35
Answer: A.4
Explanation: Pick 1 week out of 4.. 4C1 =4
Answer : A
Question: A TV is bought for Rs.6000/- and sold at a loss of 25% find its selling price?
A.s.4000/-
B.s.5560/-
C.s.3580/-
D.s.4500/-
Answer: D.s.4500/-
Explanation: 100 % ------> 6000 (100 * 60 = 600)
75 % ------> 4500 (75 * 60 = 4500)
Selling price = Rs.4500/-
Option 'D'
Question: Of the 720 students at a certain university, 25 percent are seniors. If x seniors were to graduate early and leave the university and no additional students entered or left the university, what value of x would reduce the number of seniors at the university to 20 percent?
A.30
B.36
C.42
D.45
Answer: D.45
Explanation: Sol:
180-x= 20% of (720-x)
4x=180
x=45
ANSWER:D
Question: Find the value of x. (47% of 1442 - 36% of 1412) + 66 = x?
A.1
B.2
C.3
D.6
Answer: D.6
Explanation: D) 6
Question: You forgot the three digit code of your safe. But you have written some hints to calculate the code if you forgot the code.
Below are the hints that you have written
Hint-1 : One of the numbers is correct and is placed in its correct position
5 4 7
Hint-2: Nothing is correct
5 3 0
Hint-3: Two numbers are correct but not placed at its correct position.
2 5 9
Hint-4: One number is correct but not placed at its correct position.
7 0 6
Hint-5: One number is correct but not placed at its correct position.
6 4 9
What's is the code.
A.927
B.937
C.947
D.957
Answer: A.927
Explanation: Solution:
927
1) 5 4 7 : 7 is placed correctly
2) 5 3 0 : None of the numbers is in the code
3) 2 5 9 : 2 & 9 are correct number of code but placed at wrong position
4) 7 0 6: Number 7 is there but placed at wrong position
5) 6 4 9: Number 9 is there but placed at wrong position
Answer A
Question: A box contains 30 mangoes out of which 7 are spoilt. If seven mangoes are chosen at random, find the probability that A number is selected at random from first ninty natural numbers. What is the chance that it is a multiple of either 9 or 11?
A.1/5
B.3/5
C.2/5
D.4/15
Answer: A.1/5
Explanation: The probability that the number is a multiple of 9 is 10/90. (Since 9*10 = 90).
Similarly the probability that the number is a multiple of 11 is 8/90. {Since 11*8 =
88).
Neither 9 nor 11 has common multiple from 1 to 90. Hence these events are mutually exclusive events. Therefore chance that the selected number is a multiple of 9 or 11 is (10+8)/90= 1/5.
ANSWER:A
Question: A motorist travels for 6 hours, the first half at 60 Kmph and the rest at 48 Kmph. Find the distance Traveled by him.
A.234
B.124
C.324
D.452
Answer: C.324
Explanation: Distance = 3 * 60 + 3 * 48
= 180 + 144
= 324 Km
Answer C.
Question: A person want to give his money of $1000 to his 3 children A,B,C in the ratio 6:4:5 What is the A+B share?
A.$660.67
B.$646.67
C.$666.67
D.$500.56
Answer: C.$666.67
Explanation: A's share = 1000*6/15= $400
B's share = 1000*4/15= $266.67
A+B = $666.67
Answer is C
Question: Tough and Tricky questions: Combinations.
Seven students - 4 boys and 3 girls - are to sit side by side for a makeup exam. How many ways could they arrange themselves given that no two boys and no two girls can sit next to one another?
A.12
B.36
C.72
D.288
Answer: D.288
Explanation: 4!*3!*2 = 24*6*2 = 288 ways.
Ans. D) 288
Question: Which of the following is the ninth to the right of the twentieth element from the right end of the above arrangement?
A.I only
B.II only
C.I and II
D.WEWW
Answer: D.WEWW
Explanation: Answer: Option D
Question: he L.C.M. of two numbers is 48. The numbers are in the ratio 2 : 3. Then sum of the number is:
A.30
B.40
C.38
D.36
Answer: B.40
Explanation: Let the numbers be 2x and 3x.
Then, their L.C.M. = 6x.
So, 6x = 48 or x = 8
The numbers are 16 and 24.
Hence, required sum = (16 + 24) = 40. Answer: Option B
Question: A University library checks out books for a 5-week period, but allows them to be renewed up to 6 times. What is the Maximum no.of Weeks the library will allow a book to be checked out?
A.33
B.35
C.37
D.39
Answer: B.35
Explanation: Library checkout is 5 week period and can be renewed 6 times. So he can keep for a maximum of 8 weeks.
when he is allotted the book
0-5 weeks (1st renew)
5-10 weeks (2nd renew)
10-15 weeks (3rd renew)
15-20 weeks (4th renew)
20-25 weeks (5th renew)
25-30 weeks (6th renew)- maximum renew
after that,
30-35 (submission)
So 35 weeks is maximum.
ANSWER:B
Question: X is a positive number which when increased by 17 is equal to 60 times the reciprocal of the number. Find value of X?
A.3
B.4
C.6
D.7
Answer: A.3
Explanation: Let the number be x.
Then, x + 17 =	60
x
x2 + 17x - 60 = 0
(x + 20)(x - 3) = 0
x = 3
A
Question: 25, 24, 22, ?, 15, 10
A.19
B.15
C.13
D.18
Answer: A.19
Explanation: The Pattern is - 1, - 2, -3, ...
22-3=19
Answer :A
Question: A train 120 m long is running with a speed of 66 km/hr. In what time will it pass a man who is roller skating at 12 km/hr in the direction opposite to that in which the train is going?
A.4.92
B.6.92
C.7.92
D.4.92
Answer: B.6.92
Explanation: Speed of train relative to man = 66 + 12 = 78 km/hr.
= 78 * 5/18 = 65/3 m/sec.
Time taken to pass the man = 150 * 3/65
= 6.92 sec.
Answer: B
Question: In a class of 20 students in an examination in Mathematics 2 students scored 100 Marks each, 3 get
zero each and the average of the rest was 40. What is the average Of the whole class?
A.46
B.49
C.40
D.38
Answer: C.40
Explanation: Total marks obtained by a class of 20 students
= 2 * 100 + 3 * 0 + 15 * 40
= 200 + 600 = 800
: Average marks of whole class = 800/20 = 40
Answer is C.
Question: In how many ways can A, B, C, D and E be seated in a row such that A and B are not seated next to each other?
A.24
B.72
C.56
D.76
Answer: B.72
Explanation: When the constraint on an arrangement says,Two people should not be seated together,we do just the opposite. We make them sit together! Kind of tie them with a thread and assume they are one unit!
Let's see why....
These 5 people can be arranged in 5! ways. These are the total number of ways you get.
Now, when we tie 2 people together, we have only 4 entities to arrange. We can do this in 4! ways. But in each of these entities, the two people can sit in two different ways (AB and BA). So number of ways in which these two people sit together is 4!*2!.
Now, the ways in which these two people will not be together will be 5!- 4!*2! = 4!(5 - 2) = 72
Answer :B
Question: A bowl was filled with 10 ounces of water, and 0.006 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.3%
Answer: D.3%
Explanation: Total amount of water evaporated each day during a 50-day period = .006 * 50
=.006 * 100/2
= .6/2
= .3
percent of the original amount of water evaporated during this period = (.3/10) * 100%
= 3 %
Answer D
Question: Two trains of length 100 m and 200 m are 100 m apart. They start moving towards each other on parallel tracks, at speeds 90 kmph and 72 kmph. In how much time will the trains cross each other?
A.80/6
B.80/7
C.80/9
D.80/2
Answer: C.80/9
Explanation: Relative speed = (90 + 72)* 5/18 = 45 mps.
The time required = d/s = (100 + 100 + 200)/45
= 400/45 = 80/9 sec.
Answer:C
Question: A, B and C can do a piece of work in 9 days, 14 days and 28 days respectively. How long will they taken, if all the three work together?
A.4.12 days
B.4.52 days
C.3.52 days
D.2.52 days
Answer: B.4.52 days
Explanation: 1/9 + 1/14 + 1/28 = 55/252
=> 252/55 days
=>4.52 days
ANSWER:B
Question: Two kinds of Vodka are mixed in the ratio 1:2 and 2:1 and they are sold fetching the profit 10% and 40% respectively. If the vodkas are mixed in equal ratio and the individual profit percent on them are increased by 4/3 and 5/3 times respectively, then the mixture will fetch the profit of
A.18%
B.20%
C.21%
D.40%
Answer: D.40%
Explanation: Answer: D.
Question: The table below shows the enrollment in various classes at a certain college.
Class | Number of Students
Biology | 55
Physics | 35
Calculus | 40
Although no student is enrolled in all three classes, 15 are enrolled in both Biology and Physics, 10 are enrolled in both Biology and Calculus, and 12 are enrolled in both Physics and Calculus. How many different students are in the three classes?
A.51
B.88
C.93
D.125
Answer: C.93
Explanation: No. of total students = no of students of biology + no of students of physics but not biology + no of students of calculus but not biology and physics
No. of total students = 55 + (35-15) + (40-10-12) = 55+20+18 = 93
Hence, Answer will be C.
Question: Set A contains three different positive odd integers and six different positive even integers. Set B contains two different positive odd integers and three different positive even integers. If one integer from set A and one integer from set B are chosen at random, what is the probability that the product of the chosen integers is even?
A.3/5
B.7/10
C.13/15
D.23/30
Answer: C.13/15
Explanation: There can be an odd product only if both integers are odd.
P(odd product) = 3/9*2/5 = 2/15
P(even product) = 1 - 2/15 = 13/15
The answer is C.
Question: Last year a certain bond yielded 15 percent of its face value in interest. If that interest was approximately 4 percent of the bonds selling price of $7,500, what is the bonds face value?
A.$2,000
B.$6,750
C.$7,425
D.$7,500
Answer: A.$2,000
Explanation: Interest = 0.15*face value = 0.04*7,500 --> face value = 0.04*7,500/0.15 = 2,000.
Answer: A.
Question: The sum of five numbers is 655. The average of the first two numbers is 85 and the third number is 125. Find the average of the two numbers?
A.180
B.88
C.278
D.268
Answer: A.180
Explanation: Let the five numbers be P, Q, R, S and T.
=> P + Q + R + S + T = 655.
(P + Q)/2 = 85 and R = 125
P + Q = 170 and R = 125
P + Q + R = 295
S + T = 655 - (P + Q + R) = 360
Average of the last two numbers = (S + T)/2 = 180.
Answer: A
Question: When a is divided by b, the quotient is c with remainder 3. What is a in terms of 3, b, and c?
A.b+c+3
B.b+c
C.bc
D.bc+3
Answer: D.bc+3
Explanation: a/b =c with remainder 3
i.e, a-3 = bc
a= bc+3
Answer : D
Question: A train passes a station platform in 36 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform?
A.299
B.240
C.288
D.161
Answer: B.240
Explanation: Speed = (54 * 5/18) m/sec = 15 m/sec. Length of the train = (15 x 20)m = 300 m. Let the length of the platform be x meters. Then, (x + 300)/36 = 15
==> x + 300 = 540 ==> x
= 240 m.
Answer:B
Question: The Computer Store has reduced the price of a computer by 15%.
What is the original price of the computer if the sale price is $1275?
A.1600
B.2500
C.1500
D.1200
Answer: C.1500
Explanation: Selling price = 1275/-
Reduction rate : 15%
Orginal price is : 1500/-
Answer is Option C
Question: A boy has 4 trousers and 15 shirts. In how many different ways can he select a trouser and a shirt?
A.299
B.60
C.67
D.89
Answer: B.60
Explanation: The boy can select one trouser in 4 ways.
The boy can select one shirt in 15 ways.
The number of ways in which he can select one trouser and one shirt is 4 * 15
= 60 ways.
Answer: B
Question: Two trains 140 m and 160 m long run at the speed of 60 km/hr and 40 km/hr respectively in opposite directions on parallel tracks. The time which they take to cross each other is?
A.10.6
B.10.5
C.10.1
D.10.8
Answer: D.10.8
Explanation: Relative speed = 60 + 40 = 100 km/hr.
= 100 * 5/18 = 250/9 m/sec.
Distance covered in crossing each other = 140 + 160 = 300 m.
Required time = 300 * 9/250 = 54/5 = 10.8 sec.
Answer: D
Question: The ratio of incomes of C and D is 3 : 4 and their expenditures is 4 : 5. If the savings of C is one fourth of his income then what is the ratio of savings of C and D?
A.11/19
B.12/19
C.13/19
D.14/19
Answer: B.12/19
Explanation: According to the given condition
3x - 4y = (1/4)3x
=> (3/4)3x = 4y
=> 9x = 16y
=> x/y = 16/9
so ratio of savings = (3x - 4y)/(4x - 5y) = (3*16 - 4*9)/(4*16 - 5*9) = 12/19
ANSWER:B
Question: A car averages 65 mph for the first 5 hours of a trip and averages 75 mph for each additional hour. The average speed for the entire trip was 60 mph. How many hours long is the trip?
A.9
B.8
C.7
D.6
Answer: A.9
Explanation: Let the time for which car averages 75 mph = t
60*(t+5)= 65*4 + 70 t
=>10t= 40
=> t = 4
Total duration of the trip = 5+4=9
Answer A
Question: A can do a certain work in 12 days. B is 60% more efficient than A. How many days does B alone take to do the same job?
A.15/2
B.14/2
C.15/4
D.14/4
Answer: A.15/2
Explanation: Let the total units of work done be 60.
Units of work done by A in one day = 5.
Given, B is 60% more efficient than A.
Thus, B will be able to finish 8 units of work in a day.
Therefore, time taken by B alone to complete the total work = 60/8 =15/2 days.
ANSWER:A
Question: If 4XZ + YW = 3 and XW + YZ = 6, what is the value of the expression (2X + Y)(2Z + W)?
A.9.
B.12.
C.15.
D.16
Answer: C.15.
Explanation: Expand this to get: (2X + Y)(2Z + W) = 4XZ + 2XW + 2YZ + YW
= 4 XZ + YW + 2XW + 2YZ [I rearranged the terms]
= 3 + 2XW + 2YZ [replaced 4XZ + YW with 3]
= 3 + 2(XW + YZ) factored out a 2
= 3 + 2(6)
= 3 + 12
= 15
ANSWER:C
Question: A chemical supply company has 60 liters of a 40% HNO3 solution. How many liters of pure undiluted HNO3 must the chemists add so that the resultant solution is a 50% solution?
A.12
B.15
C.20
D.24
Answer: A.12
Explanation: 60 liters of a 40% HNO3 solution means HNO3 = 24 liters in 60 liters of the solution.
Now, let x be the pure HNO3 added.
As per question,
24 + x = 50% of (60 + x)
or x =12. Hence, A
Question: The apartment on King-Williams street is an asset that its value is tramping about. From the year 1973 to 1983 it's value decreased by 16% and from 1983 to 1993 it's value increased by 16%. What is the value of the asset in 1993 if in 1973 it was worth $60,000?
A.$38,796.
B.$40,000.
C.$38,976.
D.$58,464.
Answer: D.$58,464.
Explanation: 60,000 *1.16*.84= Unit and tens digit of the expression is 6 and 7 respectively.
Only option D fulfills the condition and hence is the answer
Question: A positive integer which when added to 100, gives a sum which is greater than when it is multiplied by 100. What is the number?
A.6
B.5
C.4
D.1
Answer: D.1
Explanation: Explanation:
The number is 1
ANSWER: D
Question: If the number is divided by 3, it reduced by 36. The number is
A.A)51
B.B)50
C.C)45
D.D)54
Answer: D.D)54
Explanation: Explanation:
Let the number be x. Then,
x - (x/3) = 36 => 2x/3 = 36
=> x = 54
Answer: Option D
Question: When n is divided by 32, the remainder is 5. What is the remainder when 4n is divided by 8?
A.3
B.4
C.5
D.6
Answer: B.4
Explanation: Let n=5 (leaves a remainder of 5 when divided by 32)
4n = 4(5) =20, which leaves a remainder of 4 when divided by 8.
Answer B
Question: For any integer k > 1, the term “length of an integer” refers to the number of positive prime factors, not necessarily distinct, whose product is equal to k. For example, if k = 24, the length of k is equal to 4, since 24 = 2 × 2 × 2 × 3. If x and y are positive integers such that x > 1, y > 1, and x + 3y < 920, what is the maximum possible sum of the length of x and the length of y?
A.14
B.12
C.10
D.16
Answer: D.16
Explanation: we know that : x > 1, y > 1, and x + 3y < 1000,
and it is given that length means no of factors.
for any value of x and y, the max no of factors can be obtained only if factor is smallest noall factors are equal.
hence, lets start with smallest no 2.
2^1 =2
2^2 =4
2^3=8
2^4=16
2^5=32
2^6=64
2^7=128
2^8=256
2^9=512
2^10 =1024 (it exceeds 920, so, x can't be 2^10)
so, max value that X can take is 2^9 , for which has length of integer is 9.
now, since x =512 ,x+3y<920
so, 3y<408
==> y<136
so, y can take any value which is less than 136. and to get the maximum no of factors of smallest integer, we can say y=2^7
for 2^7 has length of integer is 7.
SO, combined together : 9+7 = 16.
D
Question: Complete the series
13, 9, 5, 1, -3,-7 ...
A.-11
B.0
C.3
D.-2
Answer: A.-11
Explanation: In the above series clearly we know we can get the next term by subtract 4 from the previous term so the answer is Option A) -11
Question: Given 2x + y + z = 3 and 5x + 3y + z = 14, what is the value of x + y - z?
A.11
B.12
C.13
D.14
Answer: D.14
Explanation: (1) 5x + 3y + z = 14
If 2x + y + z = 3, then (2) 4x + 2y + 2z = 6
Let's subtract equation (2) for equation (1).
x + y - z = 8
The answer is D.
Question: The length of a room is 5.5 m and width is 3.75 m. Find the cost of paving the floor by slabs at the rate of Rs. 400 per sq. metre.
A.Rs. 15000
B.Rs. 8250
C.Rs. 15600
D.Rs. 16500
Answer: B.Rs. 8250
Explanation: Solution
Area of the floor = (5.5 × 3.75) m2 = 20.625 m2
∴ Cost of paving = Rs. (400 × 20.625) = 8250. Answer B
Question: City X has a population 3 times as great as the population of City Y, which has a population twice as great as the population of City Z. What is the ratio of the population of City X to the population of City Z?
A.1:8
B.1:4
C.2:1
D.6:1
Answer: D.6:1
Explanation: x= 3y, y= 2*z
X : Y , Y : Z
3 : 1 , 2 : 1
6 : 2 , 2 : 1
So, X : Z = 6 : 1
(D)
Question: Hector runs a one-product widget shop. Each month, his fixed costs, whether he produces anything or not, amount to x dollars. The marginal cost of producing and selling one widget is a constant y dollars, regardless of the number he produces. He generally can sell widgets for z dollars each. What is the minimum number of widgets he must produce, assuming he sells every widget he produces, to break even (neither make a profit nor incur a loss) in a given month?
A.x/(y - z)
B.x/(z - y)
C.x
D.x/z
Answer: B.x/(z - y)
Explanation: Two ways...
1) let t be the total number, so cost = t*y+x and selling price=t*z..
No profit no loss....t*y+x=t*z.....T=x/(z-y)...
2) choices..
The answer has to use all 3 variables x,y and z....
Only A and B are left...
In A, y will be lesser than z, so A will become NEGATIVE..
ANSWER:B
Question: Henry answered 4/5 of the questions he was given for homework in the first hour, 5/19 of the remaining questions in the second hour and the remaining x questions in the third hour where x is an integer. How many questions was Henry given for homework?
A.x
B.(95/7)*x
C.(95/14)*x
D.(95/21)*x
Answer: C.(95/14)*x
Explanation: Let Q be the number of homework questions.
Q = 4Q/5 + (5/19)(Q/5) + x
Q = 76Q/95 + 5Q/95 + x
14Q/95 = x
Q = (95/14)*x
The answer is C.
Question: Jagan went to the book shop and bought things worth Rs. 30, out of which 25 paise went on sales tax on taxable purchases. If the tax rate was 5%, then what was the cost of the tax free items?
A.Rs 22.75
B.Rs 25
C.Rs 24.75
D.Rs 26
Answer: C.Rs 24.75
Explanation: Explanation :
Solution: let the amount of taxable purchases be Rs. X.
Then, 5% of x= 25/100
=> x= (25/100 *100/5) = Rs. 5
.'. Cost of tax free items = Rs.[30-(5+0.25)] = Rs. 24.75
Answer : C
Question: A money lender lends Rs.2000 for six months at 20% p.a. rate. It the interest is reckoned quarterly than find the amount given after time limit.
A.2205
B.2201
C.2229
D.2289
Answer: A.2205
Explanation: A = 2000(21/20)2
= 2205
Answer:A
Question: An inlet pipe fill a tank in 5 hrs and outlet pipe empty same tank in 36 hrs working indiviually.how many additional number of outlet pipes of same capacity required to be opened so that tank never over flows
A.6
B.7
C.8
D.9
Answer: B.7
Explanation: Inlet pipe fills the tank in 5 hr and outlet pipe empties the tank in 36 hr.
So inlet pipe is 36/5 = 7.2 times efficient than , ensure that the an outlet pipe.
Therefore , in order to tank never overflows , we will need total 8 outlet pipes.
Already we have 1 outlet pipe , thus we need only (8-1) = 7 outlet pipes
ANSWER:B
Question: Sony and Johnny caught 80 fishes. Sony caught four times as many as Johnny. How many fishes did Johnny catch?
A.12
B.16
C.34
D.38
Answer: B.16
Explanation: s+j=80
s=4*j
j=16
ANSWER:B
Question: A train passes a station platform in 48 seconds and a man standing on the platform in 20 seconds. If the speed of the train is 54 km/hr, what is the length of the platform?
A.420 m
B.200 m
C.240 m
D.320 m
Answer: A.420 m
Explanation: Sol.
Speed = [54 * 5/18] m/sec = 15 m/sec.
Length of the train = (15 * 20) m = 300 m.
Let the length of the platform be x metres.
Then, x + 300 / 48 = 15 ⇔ x + 300 = 720 ⇔ x = 440 m.
Answer A
Question: If 9 pumps can raise 1085 tonnes of water in 10 days, working 7 hours a day; in how many days will 8 pumps raise 868 tonnes of water, working 9 hours a day?
A.6
B.7
C.8
D.9
Answer: B.7
Explanation: Explanation :
Let the required number of days be x. Then,
Less pumps, More days (Indirect Proportion)
Less water, Less days (Direct Proportion)
More hours / day, Less days (Indirect Proportion)
Pumps 8 : 9
Weight 1085 : 868
Hours/day 9 : 7 :: 10 : x
(8 x 1085 x 9 x x) = (9 x 868 x 7 x 10)
x = 9 x 868 x 7 x 10/ (8 x 1085 x 9)
x = 7
Answer : B
Question: Starting from 1 if you are asked to write first 172 digits of the natural numbers , which digit you stop at?
A.4
B.7
C.8
D.9
Answer: D.9
Explanation: 12345678910=11digits
11-20=20digits
21-90=140 digits
total 171digits are completed
next number is 91 9is 172th digit & 1 is 173rd digit
ANSWER:D