RikoteMaster/aqua-rat-mcqa huggingface dataset:
Question: Tom can lay bus route between twogiven bus stop in 16 days and Andy can do the same job in 12 days. With help of John, they did the job in 4 days only. Then, John alone can do the job in how many days?
A.9 1/5
B.9 3/5
C.9 5/7
D.10 1/5
Answer: B.9 3/5
Explanation: (A + B + C)'s 1 day's work =	1	,
4
A's 1 day's work =	1	,
16
B's 1 day's work =	1	.
12
Therefore C's 1 day's work =	1	-	(	1	+	1	)	=	(	1	-	7	)	=	5	.
4	16	12	4	48	48
So, C alone can do the work in	48	= 9 3	/5days.
5	5
B
Question: At Company K, 20 percent of the employees are secretaries and 60 percent are salespeople. If there are 45 other employees of Company K, how many employees does Company K have?
A. 160
B. 180
C. 190
D. 225
Answer: D. 225
Explanation: Let the total number of employees in the company be x
% of secretaries = 20%
% of salespeople = 60%
% of of employees other than secretaries and salespeople = 100 - 80 = 20%
But this number is given as 45
so 20% of x = 45
x = 225
Therefore there a total of 225 employees in the company K
Correct answer - D
Question: The diagonal of a rectangle is cm and its area is 20 sq. cm. The perimeter of the rectangle must be:
A.18
B.77
C.625
D.276
Answer: A.18
Explanation: Explanation:
(or) {\color{Black} l^{2}+b^{2}=41}
Also,
{\color{Black} (l+b)^{2}=l^{2}+b^{2}+2lb}
= 41 + 40 = 81
(l + b) = 9.
Perimeter = 2(l + b) = 18 cm.
Answer: A) 18
Question: Series Problem like 4 12 x 44 46 132 134 begin of the Skype highlighting 44 46 132 134 end of the Skype highlighting. Find x?
A.13
B.14
C.15
D.16
Answer: B.14
Explanation: 134-132=2
46-44=2
x-12=2
x=14
ANSWER:B
Question: in a division sum the divisor is 12 times the quotient and 5 times the remainder.if the remainder is 48 what is the dividend
A.4748
B.4848
C.4846
D.4847
Answer: B.4848
Explanation: Dividend = divisor*quotient + remainder
divisor = 5*remainder = 5*48 = 240
now,
divisor = 12* quotient
240 = 12*quotient
quotient = 240/12 = 20
Dividend = divisor*quotient + remainder
Dividend = (240*20) + 48 = 4848
ANSWER:B
Question: We bought 85 hats at the store. Blue hats cost $6 and green hats cost $7. The total price was $560. How many green hats did we buy?
A.A)36
B.B)50
C.C)40
D.D)42
Answer: B.B)50
Explanation: Let B be the number of blue hats and let G be the number of green hats.
B+G=85.
B=85-G.
6B+7G=560.
6(85-G)+7G=560.
510-6G+7G=560.
G=560-510=50.
The answer is B.
Question: Gary’s Gas Station serves an average of 15 cars per hour on Saturdays, 10 cars per hour on Sundays, and 9 cars per hour on all other days of the week. If the station is open from 6 a.m. to 10 p.m. every day, how many cars does Gary’s station serve over the course of a typical week?
A.1,120
B.1,200
C.1,240
D.1,280
Answer: A.1,120
Explanation: 6 a.m. to 10 p.m. = 16 hours
Number of cars serviced on weekdays = (16 * 9 * 5)
Number of cars serviced on Saturday = (16 * 15)
Number of cars serviced on Sunday = (16 * 10)
Number of cars served in a week = 16(45 + 15 + 10) = 16 * 70 = 1120
Answer: A
Question: Suresh borrows Rs. 10,000 for 2 years at 4 % p.a. simple interest. He lends it to Ramesh at 6 % p.a. for 2 years. Find his gain in this transaction per year.
A.Rs. 150
B.Rs. 200
C.Rs. 400
D.Rs. 450
Answer: B.Rs. 200
Explanation: Explanation:
Given:
We have to calculate the gain in 2 years.
1) In case of Suresh
S.I.(10000 × 4 × 2)/100= Rs. 800
2) In case of Ramesh
S.I.(10000 × 6 × 2)/100= Rs. 1200
Suresh has a pay a simple interest of Rs. 80 to the person from whom he borrowed Rs. 1000 and Ramesh has to pay Rs. 120 to Suresh.
Hence, gain in 2 years = 1200 – 800 = Rs. 400
But we are asked to find gain of Suresh per year. Therefore,
Gain in 1 year = 400 / 2 = Rs. 200
ANSWER IS B
Question: The area of a rectangular field is equal to 300 square meters. Its perimeter is equal to 70 meters. Find the width of this rectangle.
A.W = 27
B.W = 15
C.W = 38
D.W =43
Answer: B.W = 15
Explanation: L * W = 300 : area , L is the length and W is the width.
2 L + 2 W = 70 : perimeter
L = 35 - w : solve for L
(35 - W) * W = 300 : substitute in the area equation
W = 15 and L = 20 : solve for W and find L using L = 35 - w.
correct answer B
Question: If the product of 2 integers is negative, at most how many of the integers can be negative?
A.1
B.3
C.4
D.5
Answer: A.1
Explanation: The product of 2 integers is negative
Thus an odd number of integers need to be negative to have a negative product
We are asked at most how many are required.
So, the highest odd integer before 6,i.e. 1
Correct Option : A
Question: The sum of the two numbers is 12 and their product is 35. What is the sum of the reciprocals of these numbers ?
A.12/35
B.24/32
C.31/24
D.12/26
Answer: A.12/35
Explanation: Let the numbers be a and b. Then, a + b = 12 and ab = 35.
a + b/ab = 12/35
1/b+ 1/a= 12/35
Sum of reciprocals of given numbers =12/35
ANSWER: A
Question: A and B complete a work in 20 days. A alone can do it in 40 days. If both together can do the work in how many days?
A.1.0875 days
B.0.1875 days
C.0.0675 days
D.0.075 days
Answer: D.0.075 days
Explanation: 1/20 + 1/40 = 0.075 days
ANSWER:D
Question: In a mayoral election, Candidate X received 1/5 more votes than candidate Y, and Candidate Y received 1/2 fewer votes than Z. If Z received 20,000 votes how many votes did candidate X received?
A.12000
B.22000
C.24000
D.26000
Answer: A.12000
Explanation: Z=20 --> Y received 1/2 fewer votes than Z --> Y=Z-1/2*Z=10;
X received 1/5 more votes than Y --> X=Y+1/5*Y=12.
Answer: A.
Question: If a and b are odd integers, a Δ b represents the product of all odd integers between a and b, inclusive. If y is the smallest prime factor of (3 Δ 47) + 2, which of the following must be true?
A.y is greater than 50
B.30 ≤ y ≤ 50
C.10 ≤ y < 30
D.3 ≤ y < 10
Answer: A.y is greater than 50
Explanation: (3 Δ 47) + 2 = 3*5*7*...*47+2 = odd + 2 = odd.
Now, 3*5*7*...*47 and 3*5*7*...*47 +2 are consecutive odd numbers. Consecutive odd numbers are co-prime, which means that they do not share any common factor but 1. For example, 25 and 27 are consecutive odd numbers and they do not share any common factor but 1.
Naturally every odd prime between 3 and 47, inclusive is a factor of 3*5*7*...*47, thus none of them is a factor of 3*5*7*...*47 +2. Since 3*5*7*...*47+2 = odd, then 2 is also not a factor of it, which means that the smallest prime factor of 3*5*7*...*47 +2 is greater than 50.
Answer: A.
Question: If -3x > 9, which of the following must be true?
A.x < -3
B.x < -2
C.x > 3
D.x > -2
Answer: A.x < -3
Explanation: -3x > 9
=> -x > 3
=> x < - 3
Answer A
Question: Boy sells a book for Rs. 810 he gets a loss of 10 %, To gain 10%, what should be the SP?
A.430
B.990
C.550
D.590
Answer: B.990
Explanation: Cost price = 810/90 x 100 = 900
To gain 10% = 900 x 10/100 = 90
SP = CP + gain = 900 + 90 = 990
Answer : B
Question: Each of the 59 members in a Arts class is required to sign up for a minimum of one and a maximum of three academic clubs. The three clubs to choose from are the poetry club, the history club, and the writing club. A total of 22 students sign up for the poetry club, 27 students for the history club, and 28 students for the writing club. If 6 students sign up for exactly two clubs, how many students sign up for all three clubs?
A.2
B.5
C.6
D.8
Answer: C.6
Explanation: Each of the 59 members in a Arts class is required to sign up for a minimum of one and a maximum of three academic clubs. Total = G1 + G2 + G3 - (# In exactly 2) - 2*(# in 3 sets)
59 = 22+27+28 - (6) - 2x
so, # In 3 sets = 6=C
Question: A manufacture of printer toner adjusts its price of color toner from $33 to $35 a cartridge and the price of standard black ink toner from $29 to $30 a cartridge if a document printing center spends an average of $1555 a month for toner of which 3/5 is for color cartridges how much more per month will the printing center spent?
A.78
B.79
C.60
D.80
Answer: A.78
Explanation: Total money spend per month = 1555
Money spend on color toner cartridges = 3/5*1555
= 933
Money spend on black ink toner cartridges = 2/5*1555
= 622
Number of color toned cartridges bought = 933/33
Number of black ink toned cartridges bought = 622/29
New price of color toned cartridges bought = 933/33*35
New price of black ink toned cartridges bought = 622/29*30
Total price = 1632.993
Additional money spend = Rs77.993
ANSWER:A
Question: Dany bought a total of 20 game cards some of which cost $0.25 each and some of which cost $0.15 each. If Dany spent $4.2 to buy these cards, how many cards of each type did he buy?
A.6
B.7
C.8
D.9
Answer: C.8
Explanation: Let X be the number of cards that cost $0.25 each and Y the number of cards that cost $0.15 each. The total number of cards is 20. Hence
X + Y = 20
If X is the number of cards at $0.25, then the X cards cost
0.25 X
If Y is the number of cards at $0.15, then the Y cards cost
0.15 Y
The total cost of the X cards and the the Y cards is known to be $4.2 and also given by
0.25 X + 0.15 Y = 4.2
We now need to solve the system of equations
X + Y = 20
0.25 X + 0.15 Y = 4.2
The first equation gives Y = 20 - X. Substitute y by 20 - x in the second equation and solve
0.25 X + 0.15 (20 - X) = 4.2
X(0.25 - 0.15) + 3 = 4.2
0.1 X = 1.2
X = 12 and Y = 20 - 12 = 8
correct answer C
Question: A certain sum is invested at simple interest at 18% p.a. for two years instead of investing at 12% p.a. for the same time period. Therefore the interest received is more by Rs. 300. Find the sum?
A.7000
B.2500
C.2778
D.2800
Answer: B.2500
Explanation: Let the sum be Rs. x.
(x * 18 * 2)/100 - (x * 12 * 2)/100 = 300 => 36x/100 - 24x/100 =300
=> 12x/100 = 300 => x = 2500.Answer:B
Question: A man can row with a speed of 15 kmph in still water. If the stream flows at 5 kmph, then the speed in downstream is?
A.22
B.28
C.20
D.10
Answer: C.20
Explanation: M = 15
S = 5
DS = 15 + 5 = 20
Answer:C
Question: What is the smallest positive integer x, such that 1,152x is a perfect cube?
A.4
B.6
C.8
D.12
Answer: D.12
Explanation: We need to make 1152x a perfect cube, hence we need to have the powers a multiple of 3
1152 = 2^7*3^2
The minimum value of x for which 1152x is a perfect cube = 2^2*3 = 12
Correct Option: D
Question: Two persons start running simultaneously around a circular track of length 300 m from the same point at speeds of 15 km/hr and 25 km/hr. When will they meet for the first time any where on the track if they are moving in opposite directions?
A.22
B.74
C.77
D.27
Answer: D.27
Explanation: Time taken to meet for the first time anywhere on the track
= length of the track / relative speed
= 300 / (15 + 25)5/18 = 300* 18 / 40 * 5 = 27 seconds.
Answer: D
Question: 40 litres of diesel is required to travel 600 km using a 800 cc engine. If the volume of diesel required to cover a distance varies directly as the capacity of the engine, then how many litres of diesel is required to travel 800 km using 1200 cc engine?
A.80 litres
B.90 litres
C.120 litres
D.170 litres
Answer: A.80 litres
Explanation: Explanatory Answer
To cover a distance of 800 kms using a 800 cc engine, the amount of diesel required = 800/600*40 = 53.33 litres.
However, the vehicle uses a 1200 cc engine and the question states that the amount of diesel required varies directly as the engine capacity.
i.e., for instance, if the capacity of engine doubles, the diesel requirement will double too.
Therefore, with a 1200 cc engine, quantity of diesel required = 1200/800*53.33 = 80 litres.
Answer A
Question: A person covered one-fourth of the total distance at 12 kmph and remaining distance at 24 kmph. What is the average speed for the total distance?
A.19 (1/8)kmph
B.19 (1/5)kmph
C.21 (7/3)kmph
D.27 (1/3)kmph
Answer: B.19 (1/5)kmph
Explanation: Let the total distance be x km
total time taken = (x/4)/12 + (3x/4)/24 = x/48+ x/32 = 5x/96
Average speed = x/(5x/96) = 96/5 kmph
= 19 1/5 kmph.
Answer:B
Question: A rower can row upstream at 7 km/hr and downstream at 11 km/hr. What is the rower's rate in still water?
A.7.5 km/hr
B.8.0 km/hr
C.8.5 km/hr
D.9.0 km/hr
Answer: D.9.0 km/hr
Explanation: The rate in still water is 1/2 * (11 + 7) = 9 km/hr
The answer is D.
Question: A man is 34 years older than his son. In two years, his age will be twice the age of his son. The present age of the son is?
A.16
B.19
C.15
D.32
Answer: D.32
Explanation: Let the son's present age be x years.
Then, man's present age = (x + 24) years.
(x + 34) + 2 = 2(x + 2)
x + 36 = 2x + 4
=> x =32 .
Answer: D
Question: A and B together can complete a work in 12 days. A alone can complete it in 20 days. If B does the work only for half a day daily, then in how many days A and B together will complete the work?
A.22
B.88
C.15
D.66
Answer: C.15
Explanation: B's 1 day work = (1/12 - 1/20) = 1/30
Now, (A + B)'s 1 day work = (1/20 + 1/60) = 1/15
So, A and B together will complete the work in 15 days.
Answer: C
Question: A fruit seller had some apples. He sells 40% apples and still has 420 apples. Originally, he had:
A.700
B.650
C.850
D.800
Answer: A.700
Explanation: Explanation :
Suppose originally he had x apples.
Then, (100 - 40)% of x = 420.
=> 60% of x = 420
=> 60 * x /100 = 420
=> x = (420 * 100) / 60
=> x = 700
Hence A is the answer
Answer : A
Question: A computer is programmed to multiply consecutive even integers 2*4*6*8*…*n until the product is divisible by 1419, What is the value of n?
A.86
B.38
C.62
D.122
Answer: A.86
Explanation: Factorise 1419.. 3*11*43..
So n has to be a multiple of largest prime number,61..
So n=2*43=86..
Ans :A
Question: Let A be the event that a randomly selected two digit number is divisible by 2 and let B be the event that a randomly selected two digit number is divisible by 5. What is P(A and B)?
A.1/18
B.1/10
C.1/5
D.1/3
Answer: B.1/10
Explanation: P(A and B) = 1/2*1/5 = 1/10
The answer is B.
Question: If the area of a square with sides of length 12 centimeters is equal to the area of a rectangle with a width of 6 centimeters, what is the length of the rectangle, in centimeters?
A.4
B.8
C.12
D.24
Answer: D.24
Explanation: Let length of rectangle = L
12^2 = L*4
=> L = 144/6 = 24
Answer D
Question: Find the number of square tiles to cover the floor of a room measuring 4 m * 9 m leaving 0.25 m space around the room. A side of square tile is given to be 25 cms?
A.366
B.476
C.296
D.176
Answer: B.476
Explanation: 3 1/2 * 8 1/2
= 1/4 * 1/4 * x => x
= 476
B
Question: Excluding stoppages, the average speed of a bus is 60 km/hr and including stoppages, the average speed of the bus is 40 km/hr. For how many minutes does the bus stop per hour?
A.20 min
B.30 min
C.40 min
D.35 min
Answer: A.20 min
Explanation: A
20 min
In 1hr, the bus covers 60 km without stoppages and 40 km with stoppages.
Stoppage time = time take to travel (60 - 40) km i.e 20 km at 60 km/hr.
stoppage time = 20/60 hrs = 20 min.
Question: If P represents the product of the first 13 positive integers, which of the following must be true?
I. P is an even number
II. P is a multiple of 17
III. P is a multiple of 60
A.I only
B.II only
C.I & III only
D.None of the above
Answer: C.I & III only
Explanation: The correct answer is I and III
C
Question: In an election between 2 candidate one have got 53% votes and
won by 1057 votes, how many votes were there ?
A.17616
B.27616
C.37616
D.15616
Answer: A.17616
Explanation: other got=100-53=47
they won bye 1057 votes so that is their difference
so,53-47=6
then,6-->1057
100-->?
( 1057*100)/6
=17616
ANSWER:A
Question: Set R includes elements {8, 2, 11, x, 3, y} and has a mean of 7 and a median of 5.5. If x < y, then which of the following is the maximum possible value of x?
A.0
B.1
C.2
D.3
Answer: D.3
Explanation: First, reach to the point of getting the equation R : x + y = 18
It should take about 20 seconds.
Then Substitute the answer choices into the equation.
I don't know what the answer choices in this case are.
But I'm sure, you would be able to eliminate at least 2 or 3 answer choices. (about 10 seconds).
Say you are left with 2 answer choices. (If you are short on time, guess One of the two and you'll have a 50% probability of getting it right.)
The Median (of 6 numbers) = 5.5. See if the AVERAGE of any two numbers among (2,3,8,11) results in the median. In this case, it does for 3 and 8. (15 seconds).
Once you know that the numbers that contribute towards Median are 3 and 8, and not x or y, then given x < y, x≤3. (about 10 seconds)=D
Question: Seven children — A, B, C, D, E, F, and G — are going to sit in seven chairs in a row. Child A has to sit next to both BG, with these two children immediately adjacent to here on either side. The other four children can sit in any order in any of the remaining seats. How many possible configurations W are there for the children?
A.240
B.480
C.720
D.1440
Answer: A.240
Explanation: MAGOOSHOFFICIAL SOLUTION:
First, we will consider the restricted elements — children ABG have to be in three seats in a row. How many “three in a row” seats are there in a row of seven seats?
X X X _ _ _ _
_ X X X _ _ _
_ _ X X X _ _
_ _ _ X X X _
_ _ _ _ X X X
There are five different “three in a row” locations for these three children. Now, for any given triplet of seats, we know A has to be in the middle, so the children could be seated B-A-G or G-A-B — just those two orders. This means the total number of configurations for these three children is 5*2 = 10.
Now, consider the non-restricted elements, the other four. Once ABG are seated, the remaining four children can be seated in any order among the remaining four seats — that’s a permutation of the 4 items —- 4P4 = 4! = 24. For any single configuration of ABG, there are 24 ways that the other children could be seated in the remaining seats.
Finally, we’ll combine with the Fundamental Counting Principle. We have 10 ways for the first three, and 24 ways for the remaining four. That’s a total number of configurations W of 24*10 = 240.
Answer = A
Question: Solve for x and check: - 3x = 12
A.-4
B.-2
C.1
D.3
Answer: A.-4
Explanation: Solution : Dividing each side by -3, we obtain
(-3x/-3)=(12/-3)
Therefore : x=-4
Check :
-3x=12
(-3*-4)=12
12=12
ANSWER : A
Question: Little John had $20.10. He spent $1.05 on sweets and gave to his two friends $1.00 each. How much money was left?
A.$17.05
B.$17.55
C.$17.15
D.$17.35
Answer: A.$17.05
Explanation: John spent and gave to his two friends a total of
1.05 + 1.00 + 1.00 = $3.05
Money left
20.10 - 3.05 = $17.05
Answer :A
Question: Five men and nine women can do a piece of work in 10 days. Six men and twelve women can do the same work in 8 days. In how many days can three men and three women do the work?
A.33
B.77
C.20
D.88
Answer: C.20
Explanation: (5m + 9w)10 = (6m + 12w)8
=> 50m + 90w = 48w + 96 w => 2m = 6w => 1m = 3w 5m + 9w = 5m + 3m = 8m
8 men can do the work in 10 days.
3m +3w = 3m + 1w = 4m
So, 4 men can do the work in (10 * 8)/4 = 20 days.
Answer:C
Question: By selling an article at Rs.800, a shopkeeper makes a profit of 25%. At what price should he sell the article so as to make a loss of 25%?
A.237
B.480
C.268
D.269
Answer: B.480
Explanation: SP = 800
Profit = 25%
CP = (SP)*[100/(100+P)]
= 800 * [100/125]
= 640
Loss = 25% = 25% of 640 = Rs.160
SP = CP - Loss = 640 - 160 = Rs.480
Answer:B
Question: If x/y =2/4, then (x-y)/x?
A.-1/2
B.-1
C.1/3
D.1
Answer: B.-1
Explanation: we have this law of fraction:
a/b=c/d= (a-c)/(b-d)
x/y=2/4 ---> x/2=y/4= (x-y)/(2-4)=(x-y)/(-1
2) ---> (x-y)/x= -2/2 = -1
Answer: B
Question: If the ratio of the sum of the first 6 terms of a G.P. to the sum of the first 3 terms of the G.P. is 343, what is the common ratio of the G.P?
A.3
B.1/3
C.2
D.7
Answer: D.7
Explanation: 343=(a1+a2+a3+a4+a5+a6)/(a1+a2+a3)
Factorize the same terms
343=1+(a4+a5+a6)/(a1+a2+a3)
Write every term with respect to r
a1=a1
a2=a1*r^1
a3=a1*r^2
.........
343=1+(a1(r^3+r^4+r^5))/(a1(1+r^1+r^2))
342=(r^3 (1+r^1+r^2))/((1+r^1+r^2))
342=r^3
r=7
D
Question: Find the value of z when the sum of 10z,(15z+20),(20z-4)and (30z+10) is 401?
A.10
B.15
C.7
D.5
Answer: D.5
Explanation: sum = 10z+(15z+20)+(20z-4)+ (30z+10) = 75z+26
75z+26 = 401
x = 375/75 = 5
Answer is D
Question: The average speed of a car is 1 4/5 times the avg speed of a bike. A tractor covers 575km in 23hrs. How much distance will the car cover in 5hrs if the speed of the bike is twice speed of the tractor?
A.450 km
B.500 km
C.360 km
D.550 km
Answer: A.450 km
Explanation: Sol. Average speed of a tractor = 25 km / h
The speed of a bike in an hour = 25 × 2 = 50 km
The speed of a car in an hour = 9/5 * 50 = 90 km
So, the distance covered by car in 5 h is
90 × 5 = 450 km
Ans.(A)
Question: There is a box with chocolates inside it. When we count the chocolates in pairs, one is left. When we count the chocolates in a group of three, two chocolates are left. When we count the chocolates in a group of four, three chocolates are left. When we count the chocolates in a group of five, four are left. When we count the chocolates in a group of six, five are left.
But when the chocolates are counted in a group of seven, no chocolate is left. Can you calculate the minimum number of chocolates that are present in the box?
A.113
B.116
C.119
D.118
Answer: C.119
Explanation: C
119
Let the minimum number of chocolates = C
When divided by 2, remainder = 1
When divided by 3, remainder = 2
When divided by 4, remainder = 3
When divided by 5, remainder = 4
When divided by 6, remainder = 5
When divided by 7, remainder = 0
Therefore, C is divisible by 7.
Whenever C is divided by any number less than 7, the remainder is 1 less than the divisor.
This implies that, C + 1 is the LCM of 2, 3, 4, 5 and 6.
Now LCM of 2, 3, 4, 5 and 6 = 60
But 60 - 1 = 59 is not divisible by 7
60 * 2 = 120
120 - 1 = 119 which is divisible by 7
Therefore, C + 1 = 120 or C = 119
Number of minimum number of chocolates in the box = 119
Question: Rahul's Mathematics test had 75 problems, 10 arithmetic, 30 algebra, 35 geometry problems.
Although he answered 70% of arithmetic, 40% of arithmetic and 60% of geometry problems correctly,
still he got less than 64% problems right. How many more questions he would have to answer more to get
passed
A.5
B.6
C.7
D.8
Answer: D.8
Explanation: Explanation:
Number of questions attempted correctly = (70% of 10 + 40% of 30 + 60% of 35)
= 7 + 12 + 21 = 40.
Questions to be answered correctly for 64% = 64% of total quations
= 64 % of 75 = 48.
He would have to answer 48 - 40 = 8
Answer: Option D
Question: Two trains started at the same time, one from A to B and the other from B to A . If they arrived at B and A respectively 16 hours and 49 hours after they passed each other the ratio of the speeds of the two trains was
A.2:1
B.3:2
C.4:3
D.7:4
Answer: D.7:4
Explanation: Explanation:
Note : If two trains (or bodies) start at the same time from points A and B towards each other and after crossing they take a and b sec in reaching B and A respectively, then: (A's speed) : (B's speed) = (b : a)
Therefore, Ratio of the speeds of two trains = = 7 : 4. Answer: D
Question: If 2x + y = 7 and x + 2y = 5, then 8xy/3 =?
A.A) 1
B.B) 8
C.C) 17/5
D.D) 18/5
Answer: B.B) 8
Explanation: 2*(x+2y = 5) equals 2x+4y=10
2x+4y=10
- 2x + y= 7
= 3y=3
Therefore Y = 1
Plug and solve...
2x + 1 = 7
2x=6
x=3
(8*3*1)/3
= 24/3
=8
B
Question: If 2 (A's capital) = 8 (B's capital) = 10 (C's capital). Then the ratio of their capitals is?
A.20:5:15
B.20:5:18
C.20:5:12
D.20:5:4
Answer: D.20:5:4
Explanation: 2A = 8B = 10 C
A:B:C = 1/2:1/8:1/10
= 20:5:4
Answer: D
Question: A class of 35 students has an average height of 180 cm. seven students whose average height is 120 cm, left the class and seven others whose average height is 140 cm, joined. Calculate the new average height of the students of the class (in cm) is?
A.204.6 cm
B.404.6 cm
C.224.6 cm
D.205.6 cm
Answer: A.204.6 cm
Explanation: Total height = 180 * 35 = 6300 cm.
Total height of those who left = 120 * 7 = 840
Total height of those who joined = 140 * 7 = 980
New average
= [6300 - 120 + 980 ] / 35 = 7160/35 cm.
= 204.6 cm
Answer:A