# Two friends

Peter can do all his work himself in 6 hours. Martin can do the same work himself in 8 hours. Peter worked first and then replaced by Martin. Whole work was done in 6.5 hours. Calculate how long Peter worked before replaced by Martin.

Result

p =  4.5 h

#### Solution:

p/6 + (6.5-p)/8 = 1

p = 4.5

p = 92 = 4.5

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