Question 1147308
Tap A takes 6 minutes to fill a tank and Tap B takes 9 minutes to fill the same tank.Pipe C can empty the tank in 15 minutes.How long will it take to fill up the tank if the pipe is in use when both tapes are turned on?
<pre><b>FYI: This will NOT be a negative value! 
So, this is INCORRECT ======> <s>{{{cross(1/18-1/15)}}} --------this will be a negative value.   The tank will never become filled this way.</s></b>.
It's filling FASTER than it's EMPTYING!
Correct answer: {{{highlight_green(matrix(1,4, 90/19, or, 4&14/19, minutes))}}}