Question 324691
John can paint a house in 4 hours and Sue can paint the same house in 6 hours,
 how much time will it take for them to paint the house together?
:
Let t = time required when working together
Let the completed job = 1 (a painted house)
:
Each will do a fraction of the job, the two fractions will add up to 1
:
{{{t/4}}} + {{{t/6}}} = 1
multiply by 12 to get rid of the denominators, results:
3t + 2t = 12
5t = 12
t = {{{12/5}}}
t = 2.4 hrs working together
:
:
Check solution
2.4/4 + 2.4/6 =
.6 + .4 = 1