Question:

The rates of working of A and B are in the ratio 3 : 4. The number of days taken by them to finish the work are in the ratio

(a) 3 : 4

(b) 9 : 16

(c) 4 : 3

(d) 16 : 9

Solution:

(c) 4 : 3

The number of days taken for working is the reciprocal of the rate of work.

i.e., number of days taken $=\frac{1}{\text { rate of work }}=\frac{1}{3 / 4}=\frac{4}{3}$