A mechanic requres 2 hours to repair a transmission, whereas an apprentice.....?

Question

A mechanic requires 2 hours to repair a transmission, whereas an apprentice requires 6 hours to make the same repairs. The mechanic worked alone for 1 hour and then stopped. How long will it take the apprentice, working alone, to complete the repairs?

Answer 1

1/2 + x/6 = 1
x/6 = 1/2
x = 3 hr.

Answer 2

The mechanic has done half the work. The apprentice has to do the other half. The apprentice needs 6 hours for the full work, so he needs 3 hours for the remaining work.

(Of course this example is not really working, because there is also the time the apprentice would need to familiarize with the specific problem, etc. ...)

Answer 3

If the mechanic can do it in 2 hours and he works for 1 hour, the job is half done. If it takes the apprentice 6 hours for a full job, it must take him 3 hours for job that is already half done.

Answer 4

So if the mechanic does half the job in one hour there is half the job left for the apprentice, so it will take him 3 hours. (This is assuming that the work is linear and the first half is not more difficult than the second etc).

Answer 5

In one hour mechanic completed 1/2 work, so rest of the work to
be completed by app.

now,

6x1/2 = 3


ans. is 3hrs.