Tap A can fill a cylindrical container in 3 minutes. Tap B can fill the same container in 15 minutes. How long would it take the two taps together to fill the container?
I always forget how to do these type of questions, please provide the solution, not only the result :)
Thanks!

Question

Tap A can fill a cylindrical container in 3 minutes. Tap B can fill the same container in 15 minutes. How long would it take the two taps together to fill the container?
I always forget how to do these type of questions, please provide the solution, not only the result :)
Thanks!

anonymous · Answer

I got it tap A fils in one minute = 1/3 cylinder

tap B fills in one minute = 1/15 cylinder

both in one minute = 1/3 + 1/15 

   = 2/5 cylinder

both fill full cylinder in = 5/2 minute

  = 2 minute and 20 seconds