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# algebra

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Ernie can paint a house in just 2 hours. Izzy can paint a house in 5 hours (because she takes breaks to read and sip lemonade  ). Working together, how long will it take them to paint 2 houses?

Feb 22, 2021

#1
+112966
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Ernie pains 1/2 a house per hour

Lizzie pains 1/5 of a house in an hour

Together they paint  1/5  +  1/2   =  7/10 of a house in an hour

So that is 10/7   hours per house

$$\frac{10hours}{7houses}*2 houses= \frac{20}{7}hours$$

So that is

2 hours  51minutes and 26 seconds  to the nearest second.

Feb 22, 2021