Math Is Fun Forum

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,421

Work done in time!

A contractor agrees to complete a work in 100 days. He engaged 140 men for the job and after doing the work for 60 days, he came to know that only half the work was completed. How many more men should he hire to finish the work in the agreed time?

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It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

mathsyperson

Moderator

Registered: 2005-06-22

Posts: 4,900

Re: Work done in time!

So, 140 men did half the work in 60 days, and the boss needs enough extra men to get the remaining work done in 40 days. So that means...[left for others]

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Why did the vector cross the road?
It wanted to be normal.

MathsIsFun

Administrator

Registered: 2005-01-21

Posts: 7,713

Re: Work done in time!

Approximately this many:

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"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

tt

Member

Registered: 2005-07-03

Posts: 32

Re: Work done in time!

He should hire 70 more men to complete the work in agreed time.

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,421

Re: Work done in time!

Excellent! You are correct! Tell us how you did it!

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It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

Nothing is better than reading and gaining more and more knowledge - Stephen William Hawking.

tt

Member

Registered: 2005-07-03

Posts: 32

Re: Work done in time!

The contractor needed 140 men X 60 days = 8400 man-days to do half the work. So he'll need 8400 more man-days to do the rest. He only has 40 days left, then he'll need   8400 man-days / 40 days = 210 men. He already has 140 men, so he has to hire 70 more men.

Last edited by tt (2005-07-14 17:53:51)