If 6 men and 9 women can do a piece of work in 7 days and 5 men and 11 women can do it in 7 days, ho

M4maths Previous Puzzles

14 Mar 2018 Work & Time

If 6 men and 9 women can do a piece of work in 7 days and 5 men and 11 women can do it in 7 days, how

many days will 15 men and 12 women take to do it?

OPtion

1) 3.5
2) 4.75
3) 3.25
4) 3.0
5) 3.75
6) 4.0
7) 4.25
8) 4.5
9) 3.33
10) None of these

Solution

Let a man's daily work is x units and that of a woman is y units.
So total amount of work, W = 7(6x + 9y) = 7(5x + 11y)

Solving we get, 42x - 35x = 77y - 63y
=> 7x = 14 y
=> y/x = 1/2 or y = (1/2)x

Now, 6 x + 9 y can do work in 7 days.
So, 6x + 4.5 x can do work in 7 days.
So, 10.5 x can do work in 7 days.

Now, 15x + 12y = 15x + 6x = 21x

Hence, if 10.5 x can do work in 7 days, 21x can do work in (10.5*7)/18 = 3.5 days.

Correct Option: 1 Best Solution (0)