Question 54

A can complete a certain work in 14 days, while B can do it in 5 days. In how many days will A and B together do the same work ?

Solution

Let total work to be done = 70 units

=> Efficiency of A = $$\frac{70}{14} = 5$$ units/day

and Efficiency of B = $$\frac{70}{5} = 14$$ units/day

Thus, efficiency of A & B together = $$5 + 14 = 19$$ units/day

$$\therefore$$ Time taken by A and B together do the same work

= $$\frac{70}{19} = 3 \frac{13}{19}$$ days

Create a FREE account and get: