You can
put this solution on YOUR website!An inlet pipe can fill Dominica's pool in 7 hr, while an outlet pipe can empty
it in 11 hours. In his haste to watch television, Dominica left both pipe open.
How long did it take to fill the pool.
:
TV is a brain destroyer, avoid it at all costs!
:
Let t = time required when both pipes are open
:
Let the completed job = 1 (full pool)
:
Fill is +, emptying is -
:
-
= 1
Multiply equation by 77:
77*
- 77*
= 77(1)
cancel out the denominators:
11t - 7t = 77
4t = 77
t =
t = 19.25 hrs or 19 hrs 15 min
:
:
Check solution
-
= 1
2.75 - 1.75 = 1, confirms our solution
