Answer:
Step-by-step explanation:
The amount formula in compound interest is:
where:
P = principal amount
r = annual interest
n = number of compounding periods
t = number of years
We already know that:
P = $2000
t = 7 (number of years from 6th to 13th bday)
n = 4 (quarterly in a year)
Then,
$9 + 20p ≤ $145