Vincen wrote: ↑

Sat Jan 30, 2021 9:40 pm

At a tanning salon, customers are charged $10 for their first visit in a calendar month and $6 for each visit after that in the same calendar month. In the last calendar month, 100 customers visited the salon, of which 30 made a second visit, and 10 made a third visit. All other customers made only one visit. If those visits were the only source of revenue for the salon, what was the revenue for the last calendar month at the salon?

A. $1220
B. $1240
C. $1300
D. $1340
E. $1880

Answer: B

Solution:

Notice that the 30 customers who made a second visit include the 10 customers who made a third visit. Therefore, 30 - 10 = 20 customers visited the salon exactly two times. Since 20 customers visited twice, they paid in total 20(10) + 20(6) = 200 + 120 = 320 dollars.

Since 10 customers visited three times, they paid in total 10(10) + 10(6) + 10(6) = 100 + 120 = 220 dollars.

Since the remaining customers visited once, those 70 remaining customers paid in total 70(10) = 700 dollars.

320 + 220 + 700 = 1240 dollars

Answer: B