Question

A plumber can do a job in 5 hours, and his apprentice can do the same job in 8 hours. What part of the job is left if they start the job and work together for 2 hours?

Answer 1

Answer: Taking the whole work as 40 units, in 1 hour the worker can produce 8 units and his student 5 units.

In 1 hour they produce 8+5=13 units and hence in 2 hours produce 26 units of work.

Thus they complete 26/40 of the work.

Remaining Work: 14/40 =7/20

Answer; 7/20th of the work is remaining after two hours of work.

Explanation: