math problem!!!!!!!!!!!!!!?

mistermetoo

If Steven can paint a house in 4 hours and Kristina can paint a house in 6 hours, how long would it take them to paint one house together?

Please show me the mathematical steps required to solve this problem. Thanks

ss4

S=Steven, K=Kristina

In 1 hour

S=1/4 and K=1/6 houses

S+K = 5/12 houses

Time to paint one house = (5/12)^-1 = 12/5 hours

esse-est-percipi

Steven=1/4 houses/hr

Kristina=1/6 houses/hr

Steven+Kristina= = 1/4 + 1/6 = 5/12 houses/hr

Time to paint one house =

1 house / (5/12 houses/hr) = 12/5 hrs

remember to cancel out units and to set up your equation in such a way so that only your desired units are left.

anonymous

They both would paint the house in 2 hours and 24 minutes