Question

Yap x can fill a tank with water in 8 minutes while tap y can fill the same tank in 5 minutes. How long will the two taps take to fill the tank if they are opened at the same time?

Answer 1

x ----> 1 fill / 8 min

y ---->1 fill / 5 min
so if n = number of fills in t min
n = x t + y t = t/8 + t/5
if n = 1 fill
1 = t/8 + t/5 = 5 t/40 + 8 t/40 = (13/40) t
t = 40/13 = 3.076923077 minutes