Question 662255
The first tap fills the basin in one hour, so its rate is one basin per hour.
The second tap fills the basin in two hours, so its rate is one half basin per hour.
The combined rate of the two taps in (1 + 1/2) basins per hour = 3/2 basins per hour.
So the two taps together can fill the basin in 2/3 hour, or 40 minutes.