Question:If 2 men and 3 boys can do a piece of work in 8 days. while 3 men and 2 boys can do it in 7 days, how long will 5 men and boys take to do it ?
A 3 days
B 4 days
C 5 days
D 6 days
/139
+ Answer
B
+ ExplanationLet 1 man's 1 day work = x and 1 boys 1 days work = y. Then, 2x + 3y
`= 1/8, 3x + 2y = 1/7`
Solving we get `: x = 1/28` and` y = 1/56`
`:. 5x + 4y = 5/28 + 4/56`
`= 14/56 = 1/4.`
So, 5 men and 4 boys can finish the work in 4 days.