cold water fills the tub in 30 mins. Hot fills in 60 mins. If both are turned on, how long to fill the tub?
Cold rate = 1tub/30 min
Hot rate = 1tub/60 min
x min ( 1tub/30min + 1tub/60min) = 1tub
x(1/30 + 1/60) = 1
x(2/60+1/60) = 1
3/60 * x = 1
x = 60/3 = 20 minutes to fill tub when both are turned on
Cold rate = 1tub/30 min
Hot rate = 1tub/60 min
x min ( 1tub/30min + 1tub/60min) = 1tub
x(1/30 + 1/60) = 1
x(2/60+1/60) = 1
3/60 * x = 1
x = 60/3 = 20 minutes to fill tub when both are turned on