Question 583032
a welder requires 25 hours to do a job.
 after the welder and an apprentice work on a job for 10 hours the wilder quits, the apprentice finishes the job in 17 hours.
 How long would it take the apprentice, working alone, to do the job
:
Let a = time required by the apprentice to do the job
Let the completed job = 1
:
From the information given, we see the apprentice worked a total of 27 hrs
:
{{{10/25}}} + {{{27/a}}} = 1
multiply by 25a, results
10a + 25(27) = 25a
10a + 675 = 25a
675 = 25a - 10a
675 = 15a
a = {{{675/15}}}
a = 45 hrs, the apprentice working alone