Question 5
A certain bus company gives discount to passengers who buy a monthly bus ticket in the form of stored-value card. The discounts are as follow: 5% discount per trip for the first 15 trips per month, 40% discount per trip starting on the 16th trip. If Ricky, going to office each morning by bus, uses the stored-value card of which its original price is USD6 per trip and if he took 40 trips last month, how much did he actually spend last month?