Question

Ruiz invests $55 at a simple interest rate of 4%. How much interest will he earn after 5 years?

Answer 1

Use the formula:
\[\Huge F = Pe^{rt}\]

Answer 2

F = Future value
P = present value
r = annual interest rate written as a decimal
t = number of years

Answer 3

\[\Huge F = 55e^{0.04 * 5}\]

Answer 4

Remember e = 2.71

Answer 5

I'll help you further.
e is a constant, and it is equal to 2.71
so
\[\huge F = 55(2.71)^{0.2}\]
\[\huge F = 55(1.22065759641)\]
\[\huge F = 67.1361678025\]
After 5 years, you'll have 67 dollars.

Answer 6

Thanks @shamil98