Question

A can do a piece of work in 50 days, and B in 40 days. They work together for 10 days, and then A leaves B to finish the work alone. How long will B take to finish it?

a) 16 days
b) 20 days
c) 25 days
d) 30 days

Answer 1

A can do a piece of work in 50 days and B in 40 days. Working together for 10 days, A and B complete 1/5 of the work. B then takes 32 additional days to finish the remaining work.

This correct answer is d)

Step-by-step explanation:

To solve this problem, we can first determine the individual rates at which A and B can complete the work. Let's say the work is represented by 1 unit.

A completes 1 unit of work in 50 days, so their rate of work is 1/50 units per day.

B completes 1 unit of work in 40 days, so their rate of work is 1/40 units per day.

When they work together for 10 days, their combined rate is the sum of their individual rates. So, in 10 days, they complete a portion of the work equal to:

(1/50 + 1/40) * 10 = 1/5 units.

After 10 days, A leaves and B is left to finish the remaining work of 4/5 units. Since B's rate is 1/40 units per day, they will take:

(4/5) / (1/40) = 32 days to finish the work.

Therefore, Option (d) 30 days is the correct answer.

This correct answer is d)