Answer:
hours of work done by assistant = 17.85
hours of work done by plumber = 35.7
Explanation:
Given data:
charges of plumber is $30
charges of assitant is $15
total labor charge is $1875
let x is the total hour of job by assistant
and 2x is total hours of job by plumber
so we have
15x + 30\times 2x = 1875
15x + 90x = 1875
105x = 1875
x = 17.85
therefore plumber work 2x i.e 35.7
hours of work done by assistant = 17.85
hours of work done by plumber = 35.7