Andrew can paint the neighbors house 3 times as fast as Bailey.
The year Andrew and Bailey worked together, it took them 7 days.
How long would it take each to paint the house?
:
Let t = time required by A to do it alone
then
3t = time required by B to do it alone
:
Let the completed job = 1
:
7%2Ft + 7%2F%283t%29 = 1
Multiply equation by 3t to get rid of the denominators, results:
21 + 7 = 3t
28 = 3t
t = 28%2F3
t = 91%2F3 days, Andrew alone
then
3*91%2F3 = 28 days, Bailey alone
:
:
Check solution on calc using decimals
(7/9.33) + (7/28) = 1.00