The annual interest rate is 8%.
Step-by-step explanation:
Step 1 :
Given that,
The Principal amount invested, P = $2400
The Simple interest earned = $ 144
The period of duration, n = 9 months = 9/12 year
step 2 :
To find the annual interest rate,
Simple interest = Pnr / 100
144 = (2400[tex]\times[/tex](9/12)[tex]\times[/tex]r) / 100
r = 14400 / (200[tex]\times[/tex]9)
r = 14400 / 1800
r = 8
∴ The annual interest rate is 8%
