Answer: It will take the largest pipe 5.5 hours to fill the swimming pool alone.
It will take the smallest pipe 16.5 hrs to fill the swimming pool alone.
It will take the other pipe 11 hours to fill the pool alone.
Step-by-step explanation: let time needed to fill the swimming pool by the largest pipe be x ... eq (1)
Let time needed to fill the swimming pool by the smallest pipe be 3x ... eq(2)
Let time needed to fill the swimming pool by the other pipe be 2x ...eq(3)
The job to be done (to fill a swimming pool) be 3/x +3/3x+3/2x=1 ... eq(4)
Multiply 6x on both sides you will get:
6(3)+2(3)+3(3)=6x
18+6+9=6x
33=6x
33/6=x
X=5.5hours
Substitute x=5.5 into EQ 2 and 3
3x=3×5.5=16.5hours
2x=2×5.5=11hours
Check: substitute the value of x into eq3/5.5+3/16.5+3/11
0.545+0.182+0.273=0.9997=1
