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A alone can complete a job in 50 days. B is 50% more efficient than A. If they work together, how much time will they take?

A.

25days

B.

60days

C.

40days

D.

20days

Answer with explanation

Answer: Option DExplanation

Per day, work done by A = 1/50

Per day, work done by B = (150/100) X (1/50) = 3/100

Together, per day, they complete = 1/50 + 3/100 = 5/100 =1/20

Therefore, they take, 20 days to complete the work together.

Workspace

Satyam and Shivam take a piece of work for Rs. 28,800. Satyam alone could do it in 36 days, the other in 48 days. With assistance they finish it in 12 days. How much remuneration the assistant should get?

A.

Rs. 10000

B.

Rs. 18000

C.

Rs. 16000

D.

Rs. 12000

Answer with explanation

Answer: Option DExplanation

Work done by Assistant = 1/12 – 1/36 – 1/48 = 5/144

Ratio of Satyam’s share, Shivam’s share and assistant’s share = 1/36 : 1/48 : 5/144 = 3 : 4 : 5

Hence, assistant’s share = 5/12 x 28800 = Rs. 12000

Workspace

A and B together can do a piece of work in 12 days while A alone can do the same work in 30 days. B alone can do it in

A.

18 days

B.

20 days

C.

15 days

D.

22 days

Answer with explanation

Answer: Option BExplanation

From the question,

B alone can do the same work = 1/((1/12 – (1/30))) = 20 days

Workspace

A certain job was assigned to a group of men to do in 20 days. But 12 men did not turn up for the job and the remaining men did the job in 32 days. The original number of men in the group was-

A.

32

B.

34

C.

36

D.

40

Answer with explanation

Answer: Option AExplanation

Let there be x men initially. They were supposed to complete the work in 20 days.

When 12 men didn’t show up the work was done in 32 days

So, x- 12 men did the work in 32 days

But x-12 men were supposed to take 20x/ (x-12) days

So, 20 x/ (x-12) = 32

so, x = 32

Workspace

A.

160 hrs

B.

128 hrs

C.

120 hrs

D.

154 hrs

Answer with explanation

Answer: Option AExplanation

1/A = 1/20 and 1/B + 1/C = 1/8 (Given)

1/A + 1/B + 1/C = 1/8 + 1/20 = 7/40

In 40 hours, working together they will complete 7 products.

Thus in 160 hours they will complete 28 products.

Workspace

A certain number of men can do a work in 60 days. If there were 8 men more it could be finished in 10 days less. How many men were there in the beginning?

A.

40

B.

35

C.

45

D.

50

Answer with explanation

Answer: Option AExplanation

Let there be m men originally to work in 60 days

If the men were m + 8, the work would be completed in 50 days.

(m+8)/m = 60/50

So, m = 40

Workspace

A can do a piece of work in 30 days. He works at it for 6 days and then B finishes it in 18 days. In what time can A and B together it ?

A.

11 days

B.

12 6/7 days

C.

14 1/2 days

D.

13 1/4 days

Answer with explanation

Answer: Option BExplanation

Let ‘B’ alone can do the work in ‘x’ days

6/30 + 18/x = 1

=> x = 22.5

1/30 + 1/22.5 = 7/90

=> 90/7 = 12 6/7 days

Workspace

A takes twice as much time as B or thrice as much time as C to finish a piece of work. Working together, they can finish the work in 2 days. B can do the work alone in

A.

3 days

B.

5 days

C.

6 days

D.

9 days

Answer with explanation

Answer: Option CExplanation

Workspace

Two pipes X and Y can separately fill a cistern in 18 and 24 hours respectively. If they are turned on alternately for one hour each, how long will it take to fill the cistern?

A.

18 hours 30 min

B.

16 hours

C.

20 hours 30 min

D.

24 hours

Answer with explanation

Answer: Option CExplanation

1/18 + 1/24 = 7/72

72/7 = 10 2/7

7/72 * 10 = 35/36 —– 20 hours

WR = 1 – 35/36 = 1/36

1 h —– 1/18

? —– 1/36 = 1/2 hours

=> 20 1/2 hours

Workspace

An air conditioner can coo the hall in 40 minutes while another takes 45 minutes to cool under similar conditions. If both air conditioners are switched on at same instance then how long will it take to cool the room approximately?

A.

24 Minutes

B.

19 minutes

C.

18 minutes

D.

22 minutes

Answer with explanation

Answer: Option DExplanation

Let the two conditioners be A and B

‘A’ cools at 40min

‘B’ at 45min

Together =(axb)/(a+b) = (45×40)/85 = 21.1764 = (approx) 22 min.

Workspace

Sakshi can do a piece of work in 20 days. Tanya is 25% more efficient than Sakshi. The number of days taken by Tanya to do the same piece of work is

A.

14

B.

15

C.

16

D.

18

Answer with explanation

Answer: Option CExplanation

Ratio of times taken by Sakshi and Tanya = 125 : 100 = 5 : 4.

Suppose Tanya takes *x* days to do the work.

*x* = 16 days.

Hence, Tanya takes 16 days to complete the work.

Workspace

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.

A.

90 days

B.

75 days

C.

100 days

D.

150 days

Answer with explanation

Answer: Option BExplanation

D alone will take 1/20 – 1/50 – 1/60 = 4/300 = 1/75

⇒ 75 days to complete the work.

Workspace

5 men and 2 boys working together can do four times as much work as a man and a boy. Working capacity of man and boy is in the ratio

A.

1:3

B.

1:2

C.

2:3

D.

2:1

Answer with explanation

Answer: Option DExplanation

Let 1 man 1 day work = x

1 boy 1 day work = y

then 5x + 2y = 4(x+y)

=> x = 2y

=> x/y = 2/1

=> x:y = 2:1

Workspace

3 men, 4 women, and 6 children can complete a work in 7 days. A woman does double the work a man does and a child does half the work a man does. How many women alone can complete this work in 7 days?

A.

5

B.

7

C.

9

D.

11

Answer with explanation

Answer: Option BExplanation

Let 1 woman’s 1 day work = x.

Then, 1 man’s 1 day work = x/2 and 1 child’s 1 day work x/4.

So, (3x/2 + 4x + + 6x/4) = 1/7

28x/4 = 1/7 => x = 1/49

1 woman alone can complete the work in 49 days.

So, to complete the work in 7 days, number of women required = 49/7 = 7.

Workspace

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