May 28, 2018

Question 1

X and Y can do a piece of work in 20 days and 12 days respectively. X started the work alone and then after 4 days, Y joined him till the completion of the work. How long did the work last?

6 days

10 days

20 days

15 days

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Work done by X in 4 days =[1/20 * 4] = 1/5 Remaining work =[1-1/5] = 4/5 (X+Y)’s 1 days work= [1/20 + 1/12] = 8/60= 2/15 Now, 2/15 work is done by X and Y in 1 day. So, 4/5 work will be done by X and Y in [15/2 * 4/5] = 6 days Hence, total time taken = (6 + 4) days = 10 days

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Question 2

P can complete a work in 12 days working 8 hours a day. Q can complete the same work in 8 days working 10 hours a day. If both P and Q work together, working 8 hours a day, in how many days can they complete the work?

5 5/11

5 6/11

6 5/11

6 6/11

P can complete the work in (12 x 8) hrs. = 96 hrs. Q can complete the work in (8 x 10) hrs. = 80 hrs. P’s1 hour’s work =1/96 and Q’s 1 hour’s work =1/80 (P + Q)’s 1 hour’s work = [1/96 + 1/80]= 11/480 So, both P and Q will finish the work in 480/11 hrs Number of days of 8 hours each =[480/11 * 1/8]=60/11 days= 5 5/11 days

Question 3

A certain number of men complete a piece of work in 60 days. IF there were 8 men more the work would have been completed in 10 days less. How many men were there originally?

30

35

40

45

If there are x workers in first case 1 man will take 60x. In second it will be 50(x+8) 60x = 50x + 400 x = 40

Question 4

A group of men can complete a job in K hours. After every 4 hours, half the number of men working at that point of time leave the job. Continuing this way if the job is finished in 16 hours, what is the value of K ?

7 hrs

7.5 hrs

8 hrs

8.25 hrs

job completed in first 4 hrs = L x 4 = 4L job completed in next 4 hrs = 4 x L/2 = 2L job completed in next 4 hrs = 4 x L/4 = L job completed in last 4 hrs = 4 x L/8 = L/2 4L + 2L + L + L/2 = KL K = 7+1/2 = 7.5 hours.

Question 5

In the beginning, Ram works at a rate such that he can finish a piece of work in 24 hrs, but he only works at this rate for 16 hrs. After that, he works at a rate such that he can do the whole work in 18 hrs. If Ram is to finish this work at a stretch, howmany hours will he take to finish this work?

12 hrs

18 hrs

23/2 hrs

22 hrs

Ram’s 16 hr work = 16/24 = 2/3. Remaining work = 1 – 2/3 = 1/3. Using work and time formula: This will be completed in 1/3 × 18 i.e. 6 hrs. So, total time taken to complete work = 16 + 6 = 22 hrs.

Question 6

A can do a piece of work in 10 days, and B can do this work in 15 days. They both started together. After three days, B left the work. In how many more days will the work be finished?

5 days

Their combined 3 day work = 3(1/10 + 1/15) = 3/6 = 1/2. Remaining work = 1 – 1/2 = ½. This will be done by A in 1/2 × 10 = 5 days.

Question 7

A can do a piece of work in 12 days. B can do this work in 16 days. A started the work alone. After how many days should B join him, so that the work is finished in 9 days?

2 days

3 days

4 days

A's work in 9 days = 9/12 = 3/4. Remaining work = 1/4. This work was done by B in 1/4 × 16 = 4 days. ∴ B would have joined A after 9 – 4 = 5 days.

Question 8

A and B can do a piece of work in 4 days, while C and D can do the same work in 12 days. In how many days will A, B, C and D do it together?

12 days

A, B, C and D will together take ¼ + 1/12 = = 4/12 = 1/3 ⇒ 3 days to complete the work.

Question 9

A, B, C, and D can do a piece of work in 20 days. If A and B can do it together in 50 days, and C alone in 60 days, find the time in which D alone can do it.

120 days

200 days

75 days

90 days

D alone will take 1/20 – 1/50 – 1/60 = 4/300 = 1/75 ⇒ 75 days to complete the work.

Question 10

12 men can complete a work in 8 days. 16 women can complete the same work in 12 days. 8 men and 8 women started working and worked for 6 days. How many more men are to be added to complete the remaining work in 1 day?

8

12

16

25

1 man 1 day work =1/96 1 woman 1 day work = 1/192 Work done in 6 days=6(8/96+8/192) = 6×18 =3/4 Remaining work = 1/4 (8 men +8 women)'s 1 day work = 1(8/96+8/192) =1/8 Remaining work =1/4 - 1/8 = 1/8 1/96 work is done in 1 day by 1 man Therefore, 1/8 work will be done in 1 day by 96 x (1/8) =12 men

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please provide the solution to the above questions.

please provide the solution to the above questions.