On a shopping trip, Rachel spent $3 on a bus ticket, $10 on a book, and $4 for a smoothie . She had $21 left after the trip. How much money did she start with?

An initial investment of $100 is now valued at $150. the annual interest rate is 5%, compounded continuously. the equation 100e0.05t = 150 represents the situation, where t is the number of years the money has been invested. about how long has the money been invested? use your calculator and round to the nearest whole number. years