One pipe can fill a swimming pool in 8 hours. Another pipe takes 12 hours. How long will it take to fill the pool if both pipes are used simultaneously?

4 answers

let t equal the fill time

the pipes each fill a fraction of the pool
the fractions sum to one (the whole pool)

one fraction is t/8
the other is t/12

t/8 + t/12 = 1

24 is the LCD

3t + 2t = 24
4.8 hrs
Isnt five divided by 24 invalid?
I don't know because I need it for RSM