Question 689225
 Person A can paint the neighbor's house 5 times as fast as Person B.
 The year A and B worked together, it took them 7 days.
 How long would it take each to paint the house?
:
Let t = time required by A to paint the house
" Person A can paint the neighbor's house 5 times as fast as Person B."
therefore:
5t = time required by B
:
Let the completed job = 1 (a painted house)
:
Each will do a fraction of the job, the two fractions add up to 1
:
{{{7/t}}} + {{{7/(5t)}}} = 1
multiply by 5t to get rid of the denominators, resulting in:
5(7) + 7 = 5t
35 + 7 = 5t
42 = 5t
t = 42/5
t = 8.4 days required by A
then
5(8.4) = 42 days required by B
:
:
:
Check this using a calc
{{{7/8.4}}} + {{{7/42}}} =
.83 + .17 = 1