Question 924604
{{{ L= -5t^2-8t+120 }}}
How many liters of water were in the bathtub when Barb pulled the plug? 120L
...
time it takes for all the water in the bathtub to drain. 
-5t^2-8t+120 = 0 Solving (tossing out negative solution for unit measure)
 t = 4.2 min to drain
*[invoke quadratic "x", -5, -8, 120]