Question

1 Men, 3 women & 4 boys can do a work in 96 hours. 2 men & 8 boys can do the same work in
80 hours. 2 men & 3 women can do the same work in 120 hours. then in how many hours 5 men
and 12 boys can do the same work ?
This question can be taken as:
m+3w+4b=1/96...1

2m+8b=1/80...2

2m+3w=1/120....3
Why are we considering the hours as 1/time, ie 1/96, 1/80, 1/120 etc

Answer 1

(m + 3w + 4 b) = 1/96

2m + 6w + 8b) = 1/48----1

(2m + 3 w) = 1/120----2

(2m + 8b) = 1/80-----3

1-,3 gives 6w = 1/120

w= 1/720

From 2,2m = 1/120-1/240 = 1/240.

5 m = 1/96

From 3, 8b = 1/80-1/240 = 1/120

12 b = 1/80

5m + 12b =11/480

Answer 43.63 hours.u