Question

Two men and six boys can cut a field in 3 hours. If the men work at 3/2 times that of the boys, how many men are required to cut the field in 2hours?

Answer 1

2/m + 6/b = 1/3
1/m = (3/2)/b

m = 18. That means one man can cut the field in 18 hours

2 men can do it in 9 hours

Answer 2

oops. I meant 9 men can do it in 2 hours.

Answer 3

thanks man.. but why is it 2/m +6/b=1/3 and not 2m+6b=3

Answer 4

thanks... but i still don't understand how got the equation. pls can you help me out?

Answer 5

you have to ask yourself. If a man can do the job in m hours, how much can he do in one hour? 1/m

So, 2 men can do 2/m of the job in one hour.

Same for the 6 boys.

So, since they all can complete the job in 3 hours, in one hour they have done 1/3 of the job.

You have to think of things in this way -- adding up all the work done by each person gets some fraction of the job done in an hour. Now go back and look at the equations. Oh, yeah -- and read the section in your text where this is covered.