Question

Sam accepted a job to brick a new home. he calculated that he can complete the job in 4 days. he hired a trainee to assist him. he has seen the trainee work and estimates that the trainee working alone would take 6 days to complete the job. how much time should the two of them working together need to brick the house? (round your answer to the nearest tenth.)

Answer 1

This is the concept of proportionality, we are required to calculate the total time it will take the two men to complete the job given that:
Sam would take 4 days and the trainee would take 6 days;
Here proceed as follows;
Proportion of worked completed by Sam in 1 day will be:
1/4

Proportion of work completed by the trainee in 1 day will be:
1/6

Proportion of worked completed by them working together in 1 day will be:
1/6+1/4
=5/12

Time taken for the to complete the entire wall will be:

12/5
= 2 2/5 days