Question

The table below shows the ticket rates for whale watching trips offered by Ocean Tours:

Age Ticket Price
Under 3 years - free
3 to 12 years - $36
Over 12 years - $48

On a certain day, the company took 92 people on whale watching trips. There were 40 children aged 12 and under, of which some children were under 3 years. If x represents the number of children under 3 years, which equation can be used to find the value of x, where C represents the total amount of money collected from tickets that day?
A.) (92 − x)36 + (92 − 40) ⋅ 48 = C
B.) (40 + x)36 + (92 − (40 + x)) ⋅ 48 = C
C.) (92 + x)36 + (92 − (40 + x)) ⋅ 48 = C
D.) (40 − x)36 + (92 − 40) ⋅ 48 = C

Answer 1

For finding the solution, you want to sum the revenue from each class of paying customers. There were 92-40 who were over 12 years and paid $48, so the revenue from those folks is (92-40)·48. This term is found in the first and last selections only.

There were 40-x customers who were in the age range 3–12 years, so paid $36 each. The revenue from them is (40-x)·36. This term is found in the last selection only.

The appropriate choice is ...

... D.) (40 - x)·36 +(92 - 40)·48 = C