Multiple Choice: Water will be both added to and drained from a bathtub at the same time for 5 minutes. The total amount of water added to the bathtub in litres will be modelled by the function f(t) = 5t, where t is the time elapsed in minutes. The total amount of water drained from the bathtub in litres will be modelled by the function g(t) = t2, where t is the time elapsed in minutes. How many litres of water will be in the bathtub after 4 minutes?

Question

anonymous · Answer

can someone please help me with this? The options are:
a. 4 
b. 16
c. 20
d. 36