Basic Maths Mcqs - Set 4

1)   Twelve men can do a work in twenty days while twenty women can finish the same work in sixteen days. Find the ratio between the capacity of a man and a woman.

a. 3:4
b. 5:4
c. 4:3
d. 5:3
Answer  Explanation 

ANSWER: 4:3

Explanation:
Part of work completed by a man in a day = 1/(12*20)
= 1/240 Part of work completed by a woman in a day = 1/(20*16) = 1/320 Ratio of their capacities
= (1/240):(1/320) = 320:240 = 4:3


2)   A can lay a railway track between two given stations in 16 days and B can do the same job in 12 days. With help of C, they did the job in 4 days only. Then, C alone can do the job in_________?

a. 4
b. 9.6
c. 9
d. 10
Answer  Explanation 

ANSWER: 9.6

Explanation:
Part of work completed by A and B in 4 days
= 4*((1/16) + (1/12))
= 7/12 C can complete 5/12th of the work in 4 days C can complete the whole job in
4÷(5/12) = 9.6 days


3)   If 10 bulls can plough 20 identical fields in 3 days working 10 hours a day, then in how many days can 30 bulls plough 32 same identical fields working 8 hours a day?

a. 2
b. 8
c. 10
d. 12
Answer  Explanation 

ANSWER: 2

Explanation:
M1*D1*W2 = M2*D2*W1
10*3*10*32 = 30*d*8*20
d = 2 days


4)   A work can be finished in 16 days by twenty women. The same work can be finished in fifteen days by sixteen men. The ratio between the capacity of a man and a woman is_________?

a. 1:3
b. 4:3
c. 2:3
d. 2:1
Answer  Explanation 

ANSWER: 4:3

Explanation:
Work done by 20 women in 1 day = 1/16

Work done by 1 woman in 1 day = 1/(16×20)
Work done by 16 men in 1 day = 1/15

Work done by 1 man in 1 day = 1/(15×16)
Ratio of the capacity of a man and woman =1/(15×16) : 1/(16×20) = 1/15 : 1/20

= 1/3 :1/4 = 4:3


5)   P, Q and R can complete a work in 24, 6 and 12 days respectively. The work will be completed in________days if all of them are working together.

a. 2
b. 3 3⁄7
c. 4 ¼
d. 5
Answer  Explanation 

ANSWER: 3 3⁄7

Explanation:
Work done by P in 1 day = 1/24
Work done by Q in 1 day = 1/6
Work done by R in 1 day = 1/12
Work done by P,Q and R in 1 day = 1/24 + 1/6 + 1/12 = 7/24
=> Working together, they will complete the work in 24/7 days = 3 3⁄7 days


6)   Two pipes P and Q can fill a cistern in 12 minutes and 16 minutes respectively. Simultaneously both the pipes are opened together, then after how much time Q should be closed so that the tank is full in 9 min ?

a. 2 min
b. 3 min
c. 4 min
d. 5 min
Answer  Explanation 

ANSWER: 4 min

Explanation:
Let Q be closed after x min. Then part filled by (P+Q) in x min + part filled by P in ( 9 – x )min
x(1/12+1/16)+(9−x)1/12=1


7)   A can do a certain job in 12 days. B is 60% more efficient than A. The number of days it takes for B to do the same piece of work, is:_________?

a. 12/6 days
b. 15/2 days
c. 23 days
d. 34 days
Answer  Explanation 

ANSWER: 15/2 days

Explanation:
Ratio of time, taken by A and B = 160 : 100 = 8 : 5
If A takes 8 days, B takes 5 days.
If A takes 12 days, B takes = [5/8×12]=15/2 days


8)   A can do piece of work in 30 days while B can do it in 40 days. In how many days can A and B working together do it ?

a. 70 days
b. 120/7 days
c. 50 days
d. 45 days
Answer  Explanation 

ANSWER: 120/7 days

Explanation:
No explanation is available for this question!


9)   A and B can do a piece of work in 21 and 24 days respectively.They start the work together and after some days, A leaves and B completes the rest of the task in 9 days. After how many days did A leave?

a. 5
b. 6
c. 7
d. 8
Answer  Explanation 

ANSWER: 7

Explanation:
Part of work completed by A in a day = 1/21 Part of work completed by B in a day = 1/24 Part of work completed by them together in a day = (1/21)+(1/24)
= 5/56 Part of work completed by B in 9 days
= 9/24 = 3/8 If A left after x days,
(5x/56)+(3/8) = 1
x = 7


10)   A,B,C, can do a work in 8,14,16 days respectively. A does the work for the first 2 days. B continues from it and finishes 2/3rd of the remaining work. C finishes the remaining work. How many days would have taken to complete the work?

a. 13
b. 11
c. 12
d. 15
Answer  Explanation 

ANSWER: 13

Explanation:
A completes 2*(1/8) = 1/4th of the work 2/3rd of the remaining work
= (3/4) * (2/3) = 1/2 B completes 1/2 of the work in
(1/2)÷(1/14) = 7 days C completes 1/4th of the work in
(1/4)÷(1/16) = 4 days They take 13 days to complete the work


11)   If 6 men working together can complete 50 identical tasks in 4 hours then how many such identical tasks can be completed if 10 men are working together for 6 hours?

a. 20
b. 25
c. 125
d. 60
Answer  Explanation 

ANSWER: 125

Explanation:
M1*D1*W2 = M2*D2*W1
Where, M – number of people working
D – time of work
W – number of tasks or work
6*4*W2 = 10*6*50
W2 = 125 tasks


12)   P works twice as fast as Q. If Q alone can complete a work in 12 days, P and Q can finish the work in________days

a. 1
b. 2
c. 3
d. 4
Answer  Explanation 

ANSWER: 4

Explanation:
Work done by Q in 1 day = 1/12
Work done by P in 1 day = 2 × (1/12) = 1/6
Work done by P and Q in 1 day = 1/12 + 1/6 = ¼
=> P and Q can finish the work in 4 days


13)   P is 30% more efficient than Q. P can complete a work in 23 days. If P and Q work together, how much time will it take to complete the same work?

a. 9
b. 11
c. 23
d. 13
Answer  Explanation 

ANSWER: 13

Explanation:
Work done by P in 1 day = 1/23
Let work done by Q in 1 day = q
q × (130/100) = 1/23
=> q = 100/(23×130) = 10/(23×13)
Work done by P and Q in 1 day = 1/23 + 10/(23×13) = 23/(23×13)= 1/13
=> P and Q together can do the work in 13 days


14)   6 men and 8 women can complete a work in 10 days. 26 men and 48 women can finish the same work in 2 days. 15 men and 20 women can do the same work in_______days.

a. 4 days
b. 6 days
c. 2 days
d. 8 days
Answer  Explanation 

ANSWER: 4 days

Explanation:
Let work done by 1 man in 1 day = m and work done by 1 woman in 1 day = b
Work done by 6 men and 8 women in 1 day = 1/10
=> 6m + 8b = 1/10
=> 60m + 80b = 1 — (1)
Work done by 26 men and 48 women in 1 day = 1/2
=> 26m + 48b = ½
=> 52m + 96b = 1— (2)
Solving equation 1 and equation 2. We get m = 1/100 and b = 1/200
Work done by 15 men and 20 women in 1 day
= 15/100 + 20/200 =1/4
=> Time taken by 15 men and 20 women in doing the work = 4 days


15)   A cistern has two taps which fill it in 12 min. and 15 min.respectively There is one outlet pipe in the cistern. When all the taps & pipe are opened, the empty cistern is full in 20 min. How long will the waste pipe (outlet) take to empty the full cistern ?

a. 10 min
b. 20 min
c. 30 min
d. 40 min
Answer  Explanation 

ANSWER: 10 min

Explanation:
Work done by waste pipe in 1 minute
=1/20−(1/12+1/15)=−1/10
Waste pipe will empty the full cistern in 10 minutes.


16)   To fill a cistern, pipes P, Q & R take 20, 15 & 12 minutes respectively. The time in minutes that the three pipes together will take to fill the cistern is:__________?

a. 5 min
b. 10 min
c. 15 min
d. 20 min
Answer  Explanation 

ANSWER: 5 min

Explanation:
No explanation is available for this question!


17)   A alone can finish a work in 10 days and B alone can do it in 15 days. If they work together and finish, then out of a total wages of Rs.75. A will get:___________?

a. 35 Rs.
b. 40 Rs.
c. 45 Rs.
d. None of these
Answer  Explanation 

ANSWER: 45 Rs.

Explanation:
Ratio of time taken by A and B= 10 : 15 = 2 : 3
Ratio of work done in the same time = 3:2, So, the money is to be divided among A and B in the ratio 3 : 2
A’s share = Rs. [75×3/5] = Rs.45.


18)   2 men and 12 women can finish a job in 4 days. 4 men and 6 women can do the same job in 5 days. Find the time taken by 1 man and 1 woman to complete the job.

a. 30 days
b. 25 days
c. 24 days
d. 20 days
Answer  Explanation 

ANSWER: 24 days

Explanation:
Part of work done by 1 man in a day = 1/m Part of work done by 1 woman in a day
= 1/w (2/m)+(12/w) = (1/4) (4/m)+(6/w) = (1/5) Solving,
1/m = 1/40 ,1/w = 1/60 (1/m)+(1/w) = 5/120 = 1/24


19)   Bilal can do a work in 15 days and Jalal in 12 days. If they work on it together for 4 days, the fraction of work that is left is________?

a. 3/5
b. 4/7
c. 2/5
d. 1/4
Answer  Explanation 

ANSWER: 2/5

Explanation:
Part of work completed by Bilal in a day = 1/15 Part of work completed by Jalal in a day = 1/12 Part of work completed by them in a day = (1/15)+(1/12) = 3/20 Part of work completed by them in 4 days = (3/20)*4 = 3/5 Fraction of work left
= 1-(3/5)
= 2/5


20)   A and B can finish a piece of work in 20 days .B and C in 30 days and C and A in 40 days. In how many days will A alone finish the job?

a. 48
b. 34(2/7)
c. 44
d. 45
Answer  Explanation 

ANSWER: 48

Explanation:
(1/A)+(1/B) = (1/20) (1/B)+(1/C) = (1/30) (1/A)+(1/C) = (1/40) Solving the three equations,
A=48