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8 answers

12 men take 14 days, so 1 man takes 12*14=168 days
15 women take 14 days, so 1 woman takes 15*14=210days

In one day a man gets 1/168 of the job done, and a woman gets
1/210 of the job done.

Let X = the number of days

Sinre there are 3 men and 5 woman,

3*X/168 + 5*X/210 = 1

3*210*X + 5*168*X = 168*210=35380

630*X + 840*X = 35380

1470*X = 35380

X = 24days


Brian was close, but he had:
Thus they are equivalent to 7 men
That means 7*14/12 = 49/6 days = 8.16 days

The last line should have been
That means 7*12/14 = 24 days


Wil2Play said:
From your statement, A man can do the work of 15/12ths, or 5/4ths of a woman. so, 3 + 5*(5/4) men = (12 + 25)/4 men = 37/4 men = 9.25

12 men can do the job in 14 days means it takes 168 man-days of work. 168/9.25 = 18.16 days

He should have had 3*(5/4) + 5 = 35/4 women = 8.75 women.
15 women can do the job in 14 days means it takes 210 woman-days of work. 210 / 8.75 = 24 days

ok, Wil fixed it!

2006-07-13 07:17:52 · answer #1 · answered by kimmyisahotbabe 5 · 1 0

[edit - oops, got the ratio reversed]

From your statement, A man can do the work of 15/12ths, or 5/4ths of a woman.

so,
3 + 5*(4/5) men
= (15 + 20)/5 men
= 7 men

12 men can do the job in 14 days means it takes 168 man-days of work.

168/7 = 24 days

2006-07-13 14:19:49 · answer #2 · answered by Will 6 · 0 0

12 men can do 1 job in 14 days.
12 men can do 1/14 of the job in one day. (They're using 1/14 of the time.)
3 men can do 1/[(14)(4)] = 1/56 of the job in one day. (There are 1/4 of the men.)

15 women can do 1 job in 14 days.
15 women can do 1/14 of the job in one day. (They're using 1/14 of the time.)
5 women can do 1/[(14)(3)] = 1/42 of the job in one day. (There are 1/3 of the women.)

Together, 3 men and 5 women do (1/56 + 1/42) of the job in one day.
1/56 + 1/42 = 3/168 + 4/168 = 7/168 = 1/24
Together, they do 1/24 of the job in one day.
They'll take 24 days to complete the job.

2006-07-13 16:37:45 · answer #3 · answered by Louise 5 · 0 0

15 women = 12 men

So, 1 woman = 12/15 man

So 5 women = 5*12/15 men = 4 men

Thus they are equivalent to 7 men

That means 7*14/12 = 49/6 days = 8.16 days

2006-07-13 14:16:11 · answer #4 · answered by ag_iitkgp 7 · 0 0

14*4 = 56

2006-07-13 14:09:53 · answer #5 · answered by Brian 3 · 0 0

24 days

2006-07-13 14:19:47 · answer #6 · answered by Shadar 4 · 0 0

That means 12men*14days/work = 1 and 15women*14days/work = 1
Thus, men = work/168days and women = work/210days

And (3men + 5 women)*x/work = 1
Substituting, (3work/168days + 5work/210days)*x/work = 1
=(work/56days + work/42days)*x/work

Since work/56days + work/42days
= 98work/2352days
= 49work/1176days
= work/24days

Then substituting, work*x/24days*work=1
And x/24days=1
Thus, x=24days

24 days is the answer.

2006-07-13 15:26:09 · answer #7 · answered by Nietzsche 1 · 0 0

It doesn't matter, as they'll outsource it anyway.

2006-07-13 14:09:32 · answer #8 · answered by Anonymous · 0 0

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