1. P can finish a work in 18 days. Q can finish the same work in 15 days. Q worked for 10 days and left the job. how many days does P alone need to finish the remaining work?

1. 8

2. 5

3. 4

4. 6

Answer & Explanation

Answer:- 4

Explanation :-

Work done by P in 1 day = 1/18

Work done by Q in 1 day = 1/15

Work done by Q in 10 days = 10/15 = 2/3

Remaining work = 1 – (2/3)= 1/3

Time taken By P to do remaning work = (1/3) / (1/18) = 6

2. 3 men and 7 women can complete a work in 10 days . But 4 men and 6 women need 8 days to complete the same work . In how many days will 10 women complete the same work?

1. 50

2. 40

3. 30

4. 20

Answer & Explanation

Answer:- 2

Explanation :-

1 Day work of (3m +7w) = 1/10

1 Day work of (4m +6w) = 1/8

4m + 6w = 1/8 ————- Multiply by 3

3m + 7w = 1/10 ————- Multiply by 4

12m + 18w = 1/10 ————-(1)

12m +28w = 1/8 ————-(2)

By Subtracting equation (2) from (1)

We get ,

10w = 1/40

Therefore , Work done by 10 women in 1 day =1/40

10 women can complete the work in 40 days

3. A and B can finish a work 30 days if they work together. They worked together for 20 days and then B left. A finished the remaining work in another 20 days. In how many days A alone can finish the work?

1. 60

2. 50

3. 40

4. 30

Answer & Explanation

Answer:- 1

Explanation :-

Work done by A & B in 1 day = 1/30

Work done by A & B in 20 days = 20 × (1/30) = 20/30 = 2/3

Remaining work = 1 – (2/3) = 1/3

A completes 1/3 work in 20 days

Therefore , A can complete the whole work in 3*20 = 60 days

4. A can complete a work in 12 days with a working of 8 hours per day. B can complete the same work in 8 days when working 10 hours a day. If A and B work together, working 8 hours a day, the work can be completed in — days.

1. 5 5⁄11

2. 4 5⁄11

3. 6 4⁄11

4. 6 5⁄11

Answer & Explanation

Answer:- 1

Explanation :-

A can complete the work in 12 days working 8 hours a day

Hours taken by A to complete the work = 12×8 = 96 hours

Work done by A in 1 hour = 1/96

B can complete the work in 8 days working 10 hours a day

Hours taken by B to complete the work = 8×10 = 80 hours

Work done by B in 1 hour = 1/80

Work done by A and B in 1 hour = 1/96 + 1/80 = 11/480

Hours taken by A & B together to complete the work = 480/11 hours

A & B works 8 hours a day

Therefore ,

Total days taken by A& B together to complete the work = (480/11)/ (8)

=> 60/11 days = 5 ^{5}⁄_{11} days

5. 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?

1. 9

2. 11

3. 13

4. 15

Answer & Explanation

Answer:- 3

Explanation :-

P’s 1 day work = 1/23

As 1/23 is equal to 130% of Q’s 1 day work , Therefore

Q’s 1 day work = [ (1/23)/130 ] *100 = 10/299

Work done by P & Q in 1 day = (1/23) + [10/(23×13)] = 23/(23×13)= 1/13

Therefore , P & Q together can do the work in 13 days