ong>Answer:

there are three different conditions are there

condition 1 :-6 men and 8 boys can do a PIECE of work in 10 days

condition 2:- 26 men and 48 boys can do the same in 2 days

condition 3:- what is time taken by 15 men and 20 boys? we have to find

We will represent boy with men with m

so from condition 1 what is time taken by 15 men and 20 boys?

so will have TOTAL available work done in 10 days

10( 6m + 8b ) ……………………………………………………………………eq 1

Same work has been done with condition TWO i.e 26 men and 48 boys can do the same in 2 days

so will have total available work done in 2 days

2 (26m + 48 b) ……………………………………………………………………eq 2

so we want total work done as per third condition i.e what is time taken by 15 men and 20 boys?

here we dont have time (days) INFO so we will consider X days

X ( 15m + 20b ) ……………………………………………………………………eq 3

the work done is same in the all conditions but manpower are different

we can WRIYE eq 1 and eq 2 as

10( 6m + 8b ) = 2 (26m + 48 b)

60m + 80b = 52m + 96b

8m = 16b

m=2b

we can write eq 1 and eq 3 as

10( 6m + 8b ) = X ( 15m + 20b )

10( 12b + 8b) = X (30b + 20b)

200b/ 50b = X

4 = X time taken by 15 men and 20 boys