Chapter 12, Problem 81CLR

To determine

To find: The time taken by the assistant to complete the job alone.

Answer to Problem 81CLR

The time taken by the assistant alone is $12\text{days}$ .

Explanation of Solution

Given:

The assistant did the job in 4 hour.

The time required to finish the job alone is 6 h.

Calculation:

Consider the unit of work to be done is $24$ .

Consider the amount of work done by the plumber in one day is,

  $\frac{24}{6}=4\text{unit}$

Consider the unit of work done by both the plumber and the assistant in one day is,

  $\frac{24}{4}=\text{6}\text{unit}$

Consider the time taken by the assistant to complete the job alone.

  $\frac{24}{6-4}=12\text{days}$