After 6 years, Federico earned $1485 in simple interest from a cd into which he initially deposited $ 9000. What was the annual interest rate of the cd?

A. 2.75% B. 5.5% C. 8.25 D. 11%

The formula for simple interest is:

I=Prt

I=interest earned

P = principal

r = rate in decimal form

t = time in years

I=Prt

1485=9000 (r) (6)

1485=54000r

Divide by 54000:

0.0275=r

Change to percent form:

r=2.75%