Question

. If 4 men or 7 boys can do a work in 29 days, then what
time will 12 men and 8 boys take to do the same work?​

Answer 1

Step-by-step explanation:

the job can be completed in

4*29 = 116 man-days

or

7*29 = 203 boy-days

:

:

"then 12 men and 8 boys will do the same work in?

:

let d = no. of days to do this

Let the completed job = 1,

:

Each will do a fraction of the job, the two fractions add up to 1

%2812d%29%2F116 + %288d%29%2F203 = 1

multiply equation by 23548 (203*116), results:

203(12d) + 116(8d) = 23548

:

2436d + 928d = 23548

:

3364d = 23548

d = 23548%2F3364

d = 7 days

:

:

Check this

%2812%2A7%29%2F116 + %288%2A7%29%2F203 =

%2884%29%2F116 + %2856%29%2F203 =

.724 + .276 = 1