Answer:
3(4+x)
which can be simplified to 12+3x
With replacement:
P(C,V)=(12/40)(28/40)
P(C,V)=336/1600
P(C,V)=21/100
So, first let's refill the barrel to the top:
37.5 + 7*2.5 = 55
Now that it's full again, let's divide the total amount by the rate of water loss:
55/2.5 = 22
It will take 22 minutes to completely empty the rain barrel
