Question

the san paulo community poool can be can be filled in 12hr if water enters through a pipe alone or in 30hr if water enters through a hose alone. If water is entering both ways how long will it take to fill the poool?

Answer 1

POOL*

Answer 2

23 hrs

Answer 3

i got 4.8

Answer 4

but i'm not very certain about that

Answer 5

IDK

Answer 6

I'm not certain about this but here we go.

lets say you have 2 pools. one fills up to a volume v with a hose in 30 hours and the other of the same volume v with a pipe in 12 hour.
If you fill the 2 pools (2v) sequentially (one after the other)

12+30=2v
it will take you 42 hours to finish.

42=2v


so How much would it have taken you if you combined them?

42/21=v

Answer 7

The last line should read

42/2=v

21