Question 551352
Painter can do the job in 6hours

he does 1/6 of the job in 1 hour

he works for 2 hours

so he completes 2/6 of the job = 1/3 

balance job = 1-1/3 = 2/3

Helper does the job in 10 hours
so he does 1/10 of the job in 1 hour.

Together they can do 1/6 + 1/10 of the job in 1 hour
=8/30 ==> 4/15 of the job in 1 hour

 4/15 of the job they do in 1 hour
2/3 of the job they will do in (2/3) /(4/15)
=2/3 * 15/4
=30/12
=2.5 hours
Balance job they complete in 2 1/2 hours

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