# Cleaners

Milan would clean up the room for 2.5 hours, Eric would take 10 hours. How long they swept the room together?

Result

t =  120 min

#### Solution:

$t_{ 1 }=1/(1/2.5+1/10)=2 \ \\ t=60 \cdot \ t_{ 1 }=60 \cdot \ 2=120 \ \text{min}$

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