Question 601577
    Justin can mow a lawn in 2 hours. David can mow a lawn in 3 hours. How long will it take them to mow one lawn together?
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Let x = time (hours) for both
then
x(1/2 + 1/3) = 1
multiplying both sides by 6:
x(3 + 2) = 6
x(5) = 6
x = 6/5
x = 1.2 hours
or
x = 1 hour and 12 minutes