If Mary takes 5 hours to paint a house and John takes 7 hours, how many hours will it take them both together?

this is your equation:


1/5 + 1/7 = 1/x


how many houses mary can paint in 1 hour: 1/5


added to how many houses john can paint in 1 hour: 1/7


equals 1 house divided by x which is the number of hours it will take them together (the 1 is 1 house)





so solve:


1/5 + 1/7 = 1/x


7x + 5x = 35 multiply everything by 35x (common denominator)


12x = 35 solve


x = 2.9 --%26gt;3 if you are rounding.


it will take them 3 hours to paint the house together





:)If Mary takes 5 hours to paint a house and John takes 7 hours, how many hours will it take them both together?
3 1/2 hours. Mary will be done with her half in 2 1/2, and she'll be kicking back with a cold one watching slow Johnnie fastidiously finish the job.If Mary takes 5 hours to paint a house and John takes 7 hours, how many hours will it take them both together?
5+7=12 divide 12 by 2 it takes 6 hrs.
6 hours
about 3 hours
i dont know. ask someone else