nice q.

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nice q.

by Ozlemg » Fri Aug 19, 2011 1:42 pm
25 men reap a field in 20 days . when should 15 men leave the work.if the whole field is to be reaped in 37-1/2 days after they leave the work?

a.5
b.7
c.15
d.24
e.none

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by winniethepooh » Fri Aug 19, 2011 2:59 pm
Answer is A- 5 days.
Let the work be 2000 completed units:
25 men take 20 days for 2000 units, So 1 man can complete 2000/25 = 80 units in 20 days.
So 1 man can complete 80/20 = 4 units in 1 day______________(1)

15 people leave the job after some days, After they leave the time taken is 37-1/2 days.
Therefore it took 10 people to complet X units in 37.5 days.

10 men can complete 4*10 = 40 units in 1 day_________from (1)
Therefore X = 37.5 * 40 = 1500 units of work.

The remainin 500 units (2000- 1500) was completed by 25 men before 15 men left the job.
Therefore, 25 men took 500 / 4*25 = 5 days to complete 500 units of work.

Therefore , answer is A.

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by alaynaik » Fri Aug 19, 2011 8:06 pm
It could also be done as follows:

Let us assume that the 15 men leave after x days,

Therefore, total men days---> 25 * 20 = 25 * x + 10 * 37 1/2 [10 because 15 men leave)

Upon solving the equation we get, x = 5 days

Hence OA = A.

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by GMATGuruNY » Sat Aug 20, 2011 3:29 am
Ozlemg wrote:25 men reap a field in 20 days . when should 15 men leave the work.if the whole field is to be reaped in 37-1/2 days after they leave the work?

a.5
b.7
c.15
d.24
e.none

Oa to follow
From : Gmatclub. forum
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