RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: A rectangular circuit board is designed to have a width of W inches, a length of L inches, a perimeter of P inches, and an area of X square inches. Which of the following equations must be true?
A.2W^2 − PW + 2X = 0
B.2W^2 + PW + 2X = 0
C.2W^2 − PW − 2X = 0
D.W^2 + PW + X = 0
Answer: A.2W^2 − PW + 2X = 0
Explanation: P = 2(L+W)-----------------1)
X= LW------------------------2)
option A is not possible why ?? because all the terms are positive.
lets try option B , put value of P and A from 1 and 2 we have,
2W^2-2(L+W)W + 2(LW)
2W^2 - 2LW - 2W^2 + 2LW=0.
hence answer is A.
Question: If x+y=4, x-y=36, for integers of x and y, x=?
A.20
B.15
C.25
D.13
Answer: A.20
Explanation: x+y = 4
x-y = 36
2x = 40
x = 20
Answer is A
Question: The length of a side of a hexagon is 4 inches. What is the perimeter?
A.22
B.23
C.24
D.25
Answer: C.24
Explanation: Hexagon. It means 6 equal sides.
p = 6(4) = 24 inches
Answer C
Question: For a positive integer n, let PnPn denote the product of the digits of nn and SnSn denote the sum of the digits of nn. The number of integers between 10 and 100 for which Pn+Sn=n
A.9
B.8
C.7
D.6
Answer: A.9
Explanation: Let the two digit number be 'ab'
Given, a × b + a + b = 10a + b
a × b = 9a
b = 9
Therefore, for b = 9, the above condition satisfies. So all the two digit numbers for which units digit is 9 are our solutions. They range from 19 to 99. Total 9 numbers.
Answer:	A
Question: In a new Engineering Hostels containing 100 rooms. Ankit Garg was hired to paint the numbers 1 to 100 on the doors.
How many times will Ankit have to paint the number eight ?
A.10 times
B.15 times
C.30 times
D.20 times
Answer: D.20 times
Explanation: D
20 times
8,18,28,38,48,58,68,78,98,80,81,82,83,84,85,86,87,88,88(2),89
Question: The profits of QRS company rose 20% from March to April, then dropped 20% from April to May, then rose 50% from May to June. What was the percent increase for the whole quarter, from March to June?
A.15%
B.32%
C.44%
D.62%
Answer: C.44%
Explanation: Assume 100 in march , then 120 in April as 20% increase , Then 96 in may as 20% decrease from April , and then 144 in june which is 150% of 96 .
So overall increase is from 100 to 144 is 44%
Answer C
Question: A 100-litre mixture of milk and water contains 36 litres of milk. 'x' litres of this mixture is removed and replaced with an equal quantum of water. If the process is repeated once, then the concentration of the milk stands reduced at 16%. What is the value of x?
A.33.33 litres
B.36.67 litres
C.37.67 litres
D.36.5 litres
Answer: A.33.33 litres
Explanation: Working formula ...
Initial Concentration*Initial Volume=Final Concentration*Final Volume.
Let X is the part removed from 100 lts.
36%(1-X/100)^2 = 16% * 100%
(1-x/100)^2=16/36------>(1-x/100)^2=(4/6)^2
100-X=400/6
x=33.33...
Ans A
Question: In a certain sequence of numbers, a1, a2, a3, ..., an, the average (arithmetic mean) of the first m consecutive terms starting with a1 is m, for any positive integer m. If a1=1, what is a13?
A.100
B.55
C.25
D.19
Answer: C.25
Explanation: As stated above, (a1+a2+a3......+a13)/13=13
therefore a1+a2+a3.......a13=169 (1)
using the same logic, we got a1+a2+a3..........+a12=144 (2)
(2)-(1) we got a13=25
C
Question: In a set of 5 black balls and 3 red balls, how many selections of 5 balls can bemade such that at least 3 of them are black balls?
A.24
B.26
C.46
D.49
Answer: C.46
Explanation: Selecting at least 3 black balls from a set of 5 black balls in a total selection of 5 balls can be
3 B and 2 R
4 B and 1 R and
5 B and 0 R balls.
Therefore, our solution expression looks like this.
5C3 * 3C2 + 5C4 * 3C1 + 5C5 * 3C0 = 46 ways.
C
Question: Working at constant rate, pump X pumped out half of the water in a flooded basement in 2 hours. The pump Y was started and the two pumps, working independently at their respective constant rates, pumped out rest of the water in 3 hours. How many hours would it have taken pump Y , operating alone at its own constant rate, to pump out all of the water that was pumped out of the basement?
A.a. 10
B.b. 12
C.c. 14
D.d. 18
Answer: D.d. 18
Explanation: rate of x=1/8
rate of x+y=1/6
rate of y=1/6-1/8=1/24
18 hours
D
Question: Donald duck can can swim his pool downstream(with the pool current helping time) in exact 40 seconds and upstream(against the pool current) in a pool in exact 60 seconds. The length of pool is 2 kilometers.
How long Donald duck can cover distance of one side at a still pool (with no current).
A.48 minutes.
B.58 minutes.
C.68 minutes.
D.88 minutes.
Answer: A.48 minutes.
Explanation: Solution:
48 minutes.
Donald duck's speed = X km/seconds
pool current speed = Y km/seconds
2/(X+Y) = 40
2/(X-Y) = 60
Solving the simultaneous equations gives X = 1/24
Therefore, to cover 2km will take 2/X = 48 seconds
Answer A
Question: If the given two numbers are respectively 6% and 18% of a third number, then what percentage is the first of the second ?
A.20%
B.25%
C.18%
D.33 1/3%
Answer: D.33 1/3%
Explanation: Here, l = 6 and m = 18
Therefore, first number = l/m x 100% of second number = 6/18 x 100% of second number = 33 1/3% of second number
ANSWER:D
Question: A invested Rs. 76,000 in a business. After few months, B joined him Rs. 57,000. At the end of the year, the total profit was divided between them in ratio 2 : 1. After bow many months did B join?
A.4
B.3
C.2
D.1
Answer: A.4
Explanation: Suppose B joined after x months. Then, B's money was invested for (12 - x)
=(76000 x 12)/(57000 x (12-x) =2/1 =912000=114000(12-x)
=114 (12 - x) = 912=12-x=8=x=4
Hence, B joined after 4 months
Answer is A.
Question: If n is a positive integer, which of the following expressions must be even?
A.(n − 1)( n + 3)
B.(n − 6)( n + 1)
C.(n − 2)( n + 6)
D.(n − 3)( n + 3)
Answer: B.(n − 6)( n + 1)
Explanation: Whether n is even or odd, (n-6)(n+1) will have one odd factor and one even factor.
The product will be even.
The answer is B.
Question: A train traveling at 100 kmph overtakes a motorbike traveling at 64 kmph in 40 seconds. What is the length of the train in meters?
A.1777 meters
B.1822 meters
C.400 meters
D.1111 mete
Answer: C.400 meters
Explanation: Answer
Concept : Distance covered by train when it crosses a moving object
When a train overtakes another object such as a motorbike, whose length is insignificant compared to the length of the train, the distance traveled by the train is equal to the length of the train.
Because the motorbike is also moving, we have to take the relative speed between the train and the motorbike and not just the speed of the train.
The length of the train = distance traveled by the train while overtaking the motorbike = relative speed between the train and the motorbike * time taken
In this case, as both the objects i.e., the train and the motorbike are moving in the same direction, the relative speed between them = difference between their respective speeds = 100 - 64 = 36 kmph.
Distance traveled by the train while overtaking the motorbike = 36 kmph * 40 seconds.
The final answer is in meters and the speed is given in kmph and the time in seconds.
So let us convert the given speed from kmph to m/sec.
1 kmph = 5/18 m/sec
Therefore, 36 kmph = 36 * 5/18 = 10 m/sec.
Relative speed = 10 m/sec. Time taken = 40 seconds.
Therefore, distance traveled = 10 * 40 = 400 meters.
Choice C
Question: Simplfy
b - [b -(a+b) - {b - (b - a+b)} + 2a]
A.a
B.2a
C.4a
D.0
Answer: D.0
Explanation: Explanation:
b-[b-(a+b)-{b-(b-a+b)}+2a]
=b-[b-a-b-{b-(2b-a)}+2a]
=b-[-a-{b-2b+a}+2a]
=b-[-a-{-b+a}+2a]
=b-[-a+b-a+2a]
=b-[-2a+b+2a]
=b-b
=0
Option D
Question: If a die has 3,4 and 1,6 and 2,5 opposite each other, then how many such dies can be made.
A.13
B.3
C.5
D.12
Answer: D.12
Explanation: there are 3 pairs . consider it A,B,C
A-(1,6)
B-(3,4)
C-(2,5)
Now the possible combinations to place A B C is 6.
because for A - 3 possible place
B- 2 POSSIBLE PLACE
C-1 POSSIBLE PLACE
3*2*1=6
NOW A HAS TWO PAIR SO POSSIBLE COMBO FOR 1 AND 6 IS 2 ..SAME FOR B AND C
2+2+2=6
SO 6+6=12
ANSWER:D
Question: The radius of a circular wheel is 1.75 m, how many revolutions will it make in traveling 1 km?
A.11000
B.11008
C.11006
D.110054
Answer: A.11000
Explanation: 2 * 22/7 * 1.75 * x = 11000
x = 1000
Answer: A
Question: A cistern can be filled by a tap in 4 hours while it can be emptied by another tap in 10 hours. If both the taps are opened simultaneously, then after how much time will the cistern get filled?
A.2.9 hrs
B.8.9 hrs
C.2.9 hrs
D.6.7 hrs
Answer: D.6.7 hrs
Explanation: Net part filled in 1 hour = (1/4 - 1/10)
= 3/20
The cistern will be filled in 20/3 hrs i.e., 6.7 hrs.
Answer:D
Question: Two pipes A and B can separately fill a tank in 2 minutes and 15 minutes respectively. Both the pipes are opened together but 4 minutes after the start the pipe A is turned off. How much time will it take to fill the tank?
A.18
B.10
C.12
D.11
Answer: B.10
Explanation: 4/12 + x/15
= 1
x = 10
Answer: B
Question: 1/3rd of work is completed by kiran in 6days. In how many days he can finish the remaining work?
A.6days
B.10days
C.12days
D.15days
Answer: C.12days
Explanation: 1/3rd work finished in 6days
2/3rd work = 2/3*3*6 = 12days
Answer is C
Question: If n is a positive integer and n^2 is divisible by 72, then the largest positive integer that must divide n is
A.6
B.12
C.24
D.36
Answer: B.12
Explanation: possible values of n = 12, 24, 36 and 48.
But it is 12 that can divide all the possible values of n. If we consider 48, it will not divide 12, 24 and 36.
Hence, 12 is the value that MUST divide n.
ANSWER:B
Question: A train of length 150 metres takes 40.5 seconds to cross a tunnel of length 300 metres. What is the speed of the train in km/hr?
A.10 km/hr.
B.20 km/hr.
C.30 km/hr.
D.40 km/hr.
Answer: D.40 km/hr.
Explanation: Sol.
Speed = [150 + 300 / 40.5] m/sec = [450 / 40.5 * 18/5] km/hr = 40 km/hr.
Answer D
Question: A car traveling at a certain constant speed takes 12 seconds longer to travel 1 kilometer than it would take to travel 1 kilometer at 75 kilometers per hour. At what speed, in kilometers per hour, is the car traveling?
A.60
B.72
C.72.5
D.73
Answer: A.60
Explanation: Many approaches are possible, one of them:
Let the distance be 1 kilometer.
Time to cover this distance at 75 kilometers per hour is 1/75 hours = 3,600/75 seconds = 48 seconds;
Time to cover this distance at regular speed is 48+12=60 seconds = 60/3,600 hours = 1/60 hours;
So, we get that to cover 1 kilometer 1/60 hours is needed --> regular speed 60 kilometers per hour (rate is a reciprocal of time or rate=distance/time).
Answer: A
Question: A certain sum of money at simple interest amounted Rs.1448 in 9 years at 4% per annum, find the sum?
A.1064
B.1080
C.1980
D.646
Answer: A.1064
Explanation: 840 = P [1 + (9*4)/100]
P = 1064
Answer:A
Question: In what time a debt of Rs.7920 due may be cleared by immediate cash down
payment of Rs.3600 at 1/2% per month
A.10years
B.20years
C.30years
D.40years
Answer: B.20years
Explanation: Explanation:
PW=100*Amount / 100+(R+T)
ANSWER IS B
Question: A person crosses a 500 m long street in 4 minutes. What is his speed in km per hour?
A.7.5
B.2.6
C.3.9
D.8.2
Answer: A.7.5
Explanation: distance = 500 meter
time = 4 minutes = 4 x 60 seconds = 240 seconds
Speed = distance/time=500/240=2.08 m/s=2.08Ã—18/5 km/hr=7.5 km/hr
Answer :A
Question: In how many ways can eight different rings be worn on four fingers of one hand?
A.10
B.12
C.70
D.60
Answer: C.70
Explanation: Required number of ways = ways of selecting 4 objects out of 8 given objects
= 8C4 = 8x 7x 6x 5 /24= 70
Answer C
Question: (1^2+2^2+3^2+.....+11^2)=?
A.506
B.345
C.365
D.385
Answer: A.506
Explanation: formula is (1^2+2^2+3^2+....+n^2=1/6 n(n+1)(2n+1)
n=11
=(1/6x11x12x23)
=506
Answer is A.
Question: The car A has an average speed of 40 miles/hour and car B has an average speed of 60. How much time(in minutes) does the car A take more than car B to cover a distance of 60 miles?
A.10
B.20
C.25
D.30
Answer: D.30
Explanation: Time taken by Car A=60 miles/40 mph
=1.5 hours=90min
Time taken by Car B=60miles/ 60mph
=1 hour = 60 min
Car A takes 30 min more than car B
Answer: D
Question: In a hotel, rooms are numbered from 101 to 550. A room is chosen at random. What is the probability that room number starts with 1, 2 or 3 and ends with 4, 5 or 6?
A.80 rooms
B.90 rooms
C.70 rooms
D.60 rooms
Answer: B.90 rooms
Explanation: There are total 450 rooms.
Out of which 299 room number starts with either 1, 2 or 3. (as room number 100 is not there) Now out of those 299 rooms only 90 room numbers end with 4, 5 or 6.
Ans : The probability is 90/450 so 90 rooms
Answer B
Question: Calculate the effect changes in dimension of a rectangle will have on its area, if length is increased by 18% and its breadth is decreased by 16%?
A.5.88% decrease
B.0.88% decrease
C.0.88% increase
D.1.88% decrease
Answer: B.0.88% decrease
Explanation: let L and B be 100 each
100 * 100 = 10000
L increase by 18% = 118
B decrease by 16% = 84
118 * 84 = 9912
0.88% decrease
ANSWER:B
Question: How many numbers from 10 to 50 are exactly divisible by 3
A.11
B.13
C.15
D.18
Answer: B.13
Explanation: 12, 15, 18, 21, 24, 27, 30, 33, 36, 39, 42, 45,48.
13 Numbers.
10/3 = 3 and 50/3 = 16 ==> 16 - 3 = 13. Therefore 13 digits
B)
Question: In an election only two candidates contested. A candidate secured 70% of the valid votes and won by a majority of 180 votes. Find the total number of valid votes?
A.430
B.450
C.436
D.434
Answer: B.450
Explanation: Let the total number of valid votes be x.
70% of x = 70/100 * x = 7x/10
Number of votes secured by the other candidate = x - 7x/100 = 3x/10
Given, 7x/10 - 3x/10 = 180 => 4x/10 = 180
=> 4x = 1800 => x = 450.
Answer:B
Question: 2 corner most boxes of a chess board(diagonally opposite) haven been cut out
there's a rectangular block = 2 sqaures of chess board , how many such blocks can be placed on the chess board ?”
A.27
B.28
C.29
D.30
Answer: D.30
Explanation: chess board has 64 squares.so we can place 32 rectangular blocks,but 2 are cut off from the corner.
hence 32-2=30 blocks
ANSWER:D
Question: If |x - 20| = 40 what is the sum of all the values of x.
A.0
B.60
C.-80
D.40
Answer: D.40
Explanation: There will be two cases
x-20 = 40 and x-20 = -40
Solve for x => x=40+20=> x=60 or x= -40 + 20 => x= -20
The sum of both values will be 60 + -20 =40
Answer is D
Question: If your mother asked you to bring her 7 water bottles, and one bottle costs 1.5 $, how much money should she give you?
A.9 $
B.9.5 $
C.10 $
D.10.5 $
Answer: D.10.5 $
Explanation: Simply multiply the cost of one bottle by its number you would buy.
The cost=7*1.5=10.5 $
So the correct choice is D
Question: At what rate of interest (compounded yearly)will Rs.10,000 amount to Rs.12100 in 2 years?
A.11%
B.8%
C.10%
D.9%
Answer: C.10%
Explanation: C.I=P(1+R/100)^N
12100=10000(1+R/100)^2
121/100=(1+R/100)^2
(11/10)^2=(1+R/100)
R=10%
ANSWER:C
Question: 15 and 5 are the first two terms in a geometric sequence. What is the arithmetic difference between the 7th term and the 9th term?
A.(40/3) * (1/3)^7
B.(40/6) * (1/3)^7
C.(40/9) * (1/3)^7
D.(1/3)^7
Answer: A.(40/3) * (1/3)^7
Explanation: Common ratio = 5/15 =1/3
7th term = 15*(1/3)^7
9th term = 15*(1/3)^9
Difference = 15 * ((1/3)^7 - (1/3)^9)
= 15 * (1/3)^7 *(1 - (1/3)^2)
= 15 * (1/3)^7 * (8/9)
= (120/9) * (1/3)^7....
= (40/3) * (1/3)^7
A
Question: The mean of 1^3,2^3,3^3,4^3,5^3 is?
A.30
B.45
C.50
D.60
Answer: B.45
Explanation: 1^3+2^3+3^3+-----+n^3 = [n(n+1)/2]^2
1^3+2^3+3^3+-----+5^3 = (5*6/2)^2 = 225
Required average is = 225/5 = 45
Answer is B
Question: Convert the 18/42 m/s into kilometers per hour?
A.3.5 kmph.
B.2.5 kmph.
C.1.2 kmph.
D.1.54 kmph.
Answer: D.1.54 kmph.
Explanation: 18/42 m/s = 18/42 * 18/5 = 1 (27/50) = 1.54 kmph.
ANSWER:D
Question: The ratio of salary of a worker in July to that in June was 21⁄2 : 21⁄4, by what % the salary of July more than salary of June. Also find by what %, salary of June was less than that of July.
A.11 1⁄9% and 10%
B.10% and 11 1⁄9%
C.Both 10%
D.Both 11 1⁄9%
Answer: A.11 1⁄9% and 10%
Explanation: Let the salary of July be 5⁄2 x
and the salary of June be 9⁄4 x
Required percentages
= 5/2x−9/4x /9/4x×100 and 5/2x−9/4x /5/2x×100
= 100⁄9% and 100⁄10% = 11 1⁄9% and 10%
Answer A
Question: In expressing a length of 77.470 km as nearly as possible with the three significant digits, find the percentage error
A.0.39%
B.0.34%
C.0.039%
D.0.035%
Answer: C.0.039%
Explanation: Explanation:
Error = (77.5 - 77.470) = 0.03
Required percentage =
0.03/ 77.470Ã—100=0.039
Option C
Question: The average of 40 numbers is 32. If two numbers namely 34 and 39 are discarded, The average of
remaining numbers is?
A.31.7
B.37.5
C.39.5
D.34.5
Answer: A.31.7
Explanation: Total of 50 numbers = 40 * 32 = 1280
Average of 38 numbers = 1280-(34+39) / 38
= 1207 / 38 = 31.7
Answer is A.
Question: The cube root of .000343 is
A.0.7
B.0.07
C.0.007
D.7
Answer: B.0.07
Explanation: Explanation:
(.000343)1/3
= (343/106)1/3
= (7*7*7/ 102*102*102)1/3
= 7/102
= 7/100 = 0.07
ANSWER B
Question: The probability that a arrow fired from a point will hit the target is 1/4. Three such arrows are fired simultaneously towards the target from that very point. What is the probability that the target will be hit?
A.19/64
B.23/64
C.23/67
D.37/64
Answer: D.37/64
Explanation: Explanation :
Probability of a arrow not hitting the target =3/4.
Probability that none of the 3 arrow will hit the target:
=>(3/4)3.
=>27/64.
Probability that the target will hit at least once
=>1−(27/64).
=>37/64.
Answer : D
Question: A and B together can do a piece of work in 3 days. If A alone can do the same work in 20 days, then B alone can do the same work in?
A.0.28 days
B.0.45 days
C.0.55 days
D.0.25 days
Answer: A.0.28 days
Explanation: B = 1/2 – 1/20 =0.28 days
ANSWER:A
Question: By travelling at 60 kmph, a person reaches his destination on time. He covered two-third the total distance in one-third of the total time. What speed should he maintain for the remaining distance to reach his destination on time?
A.30 kmph
B.28 kmph
C.26 kmph
D.24 kmph
Answer: A.30 kmph
Explanation: Let the time taken to reach the destination be 3x hours. Total distance = 60 * 3x = 180x km
He covered 2/3 * 180x = 120x km in 1/3 * 3x = x hours So, the remaining 60x km, he has to cover in 2x hours. Required speed = 60x/2x
=30 kmph.
Answer: A
Question: Find the invalid no.from the following series 10, 17, 22, 29, 34, 36
A.36
B.18
C.40
D.37
Answer: A.36
Explanation: The differences between two successive terms from the beginning are 7, 5, 7, 5, 7, 5. So, 36 is wrong.
Answer : A
Question: Present ages of X and Y are in the ratio 4:5 respectively. 6 years hence this ratio will become 5:6 respectively. What is X's present age in years?
A.35
B.24
C.37
D.39
Answer: B.24
Explanation: Let the present ages of X and Y be 4x and 5x years respectively.
Then, (4x + 6)/(5x + 6) = 5/6
6(4x + 6) = 5(5x + 6) => 24x+36 = 25x+30 => x=6
X's present age = 4x = 4*6 = 24
ANSWER: B
Question: In a 2000 m race, A beats B by 100 meters or 50 seconds. Find the speed of B?
A.10m/s
B.2m/s
C.5m/s
D.7m/s
Answer: B.2m/s
Explanation: Since A beats B by 100 m or 50 seconds,
it implies that B covers 100 m in 50 seconds.
Hence speed of B = 100/50 = 2 m/s.
Answer: B
Question: Two isosceles Triangles have equal vertical angles and their areas are in the ratio 16:36. Find the ratio of their corresponding heights .
A. 4/6
B. 5/4
C. 3/2
D. 5/7
Answer: A. 4/6
Explanation: We are basically given that the triangles are similar.
In two similar triangles, the ratio of their areas is the square of the ratio of their sides and also, the square of the ratio of their corresponding heights.
Therefore, area/AREA=height^2/HEIGHT^2=16/36 --> height/HEIGHT=4/6.
Answer: A.
Question: 65% of x = 20% of 422.50. Find the value of x?
A.100
B.130
C.150
D.180
Answer: B.130
Explanation: 65% of x = 20% of 422.50
Then, 65/100 * x = 20/100 * 4225/10
x = 845/10 * 100/65 = 130
Answer is B
Question: The area of a square garden is Q square feet and the perimeter is P feet. If Q=2P+48, what is the perimeter of the garden in feet?
A.36
B.40
C.44
D.48
Answer: D.48
Explanation: Let x be the length of one side of the square garden.
x^2 = 8x + 48
x^2 - 8x - 48 = 0
(x-12)(x+4) = 0
x = 12, -4
P = 4(12) = 48
The answer is D.
Question: The perimeter of a triangle is 24 cm and the inradius of the triangle is 2.5 cm. What is the area of the triangle?
A.30 cm2
B.85 cm2
C.65 cm2
D.45 cm2
Answer: A.30 cm2
Explanation: Area of a triangle = r * s
Where r is the inradius and s is the semi perimeter of the triangle.
Area of triangle = 2.5 * 24/2 = 30 cm2
Answer:A
Question: What is the rate percent when the simple interest on Rs.9100 amount to Rs.455 in 3 Years?
A.3.7%
B.5.7%
C.6.7%
D.8.7%
Answer: A.3.7%
Explanation: 455 = (4100*3*R)/100
R = 3.7%
Answer: A
Question: How many digits are in the number 50^8 × 8^3 × 11^2?
A.22
B.20
C.19
D.18
Answer: C.19
Explanation: calculate the Number of 0's through the powers of 10
50^8 × 8^3 × 11^2 = (5^2*2)^8*2^9*11^2 = 5^16*2^17*11^2 = 2*11^2*10^16 = 242*10^16
Hence we would have 16 trailing 0's and the three digits from 242
Total digits = 3 + 16 = 19
Correct Option: C
Question: . If the sides of two cubes are in the ratio 3: 1 the ratio of their total surface area is?
A.3:2
B.9:5
C.9:1
D.9:9
Answer: C.9:1
Explanation: Explanation:
a1 : a2 = 3 : 1
6 a12 : 6 a22 = 9: 1
Answer: Option C
Question: If mn > 0, which of the following must be negative?
A.mn
B.mn^2
C.m/-n
D.m/n
Answer: C.m/-n
Explanation: Given mn> 0 So both will be the positive integers. If both are positive, then A,B,D,E also positive.
Answer :C
Question: A thief goes away with a SANTRO car at a speed of 40 kmph. The theft has been discovered after half an hour and the owner sets off in a bike at 50 kmph when will the owner over take the thief from the start?
A.2 hours
B.9 hours
C.6 hours
D.3 hours
Answer: A.2 hours
Explanation: Explanation:
|-----------20--------------------|
50 40
D = 20
RS = 50 – 40 = 10
T = 20/10 = 2 hours
Answer: Option A
Question: If the radius of a circle is increased by 20% then the area is increased by:
A.44
B.219
C.16
D.18
Answer: A.44
Explanation: Explanation:
Let say radius = πr2πr2 = π102π102 = 100π100π
New radius = 10 × 120% = 12
New area = π122π122 = 144π144π
Increment = 144π−100π100π×100144π−100π100π×100 = 44%
Answer: A
Question: A certain fruit stand sold apples for $0.70 each and guava for $0.50 each. If a customer purchased both apples and bananas from the stand for a total of $6.30, what total number of apples and bananas did the customer purchase ?
A.12
B.13
C.11
D.14
Answer: C.11
Explanation: Some multiple of 7 + Some multiple of 5 should yield 63. To get to a some multiple of 5, we should ensure that a 3 or 8 (5+3) should be a multiple of 7.
63 is a direct multiple of 7, however in this case there won't be any guava. Hence the next option is to look for a multiple of 7 that has 8 as the unit digit. 28 satisfies this hence no. of apples is 4 and no of bananas is 7 .
C
Question: Cathy and Jim begin running at the same time and they start at the same place on a straight path. Cathy runs at 10 miles per hour, and Jim runs at 6 miles per hour. After 18 minutes, Cathy stops to stretch. If it takes Cathy 27 minutes to stretch and Jim continues to run during this time, how many minutes will it take Cathy to catch up to Jim?
A.20.5
B.21.5
C.22.5
D.23.5
Answer: C.22.5
Explanation: In 18 minutes, Cathy runs 3 miles.
In 45 minutes, Jim runs 4.5 miles.
Cathy can catch Jim at a rate of 4 miles per hour.
Since Jim is ahead by 1.5 miles, it will take Cathy 1.5 / 4 hours = 22.5 minutes to catch Jim.
The answer is C.
Question: A windmill is taking advantage of strong air currents in order to produce electrical energy. On a typical day the wind speed is around 20 mph and in that speed the windmill produces 600 kw/h (kilowatts per hour). On a stormy day a windmill produces 20% more energy. How much kw/h can three windmills produce in two hours on a stormy day?
A.2880.
B.4320.
C.5780.
D.5760.
Answer: B.4320.
Explanation: Efficiency per machine = 600 watt/hr
Efficiency due to increase in wind speed = 600*120% => 720 watt/hr
Production by each machine in 2 hours is 720*2 => 1440 watt
Production by 3 machines => 1440 watt * 3 = 4320 watt
Answer will be (B)