Basic Maths Mcqs

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:_________?

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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
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

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?

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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
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

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?

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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
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

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?

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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
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

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

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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
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

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?

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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
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

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.

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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
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

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 ?

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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

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.