Chain Rule Q9

9. If 5 men or 9 women can do a piece of work in 19 days, then in how many days will 3 men and 6 women do the same work?

[A]12

[C] 18

[B]15

[D] 21

Answer : B

Explanation :

Let the required number of days be x.

5 men = 9 women 3 men = 9 5 x 3 Women =  27 5  Women.

(3 men and 6 women) = 27 5 + 6 Women =  57 5  Women.

Now, More women, Less days (Indirect Proportion)

57 5  : 9 :: 19 : x 57 5  x x = 9 x 19 x = 9 x 19 x 5 57  = 15