To find the simple interest earned on an investment, we use the formula:
I = P * r * t
Where:
I = simple interest earned
P = principal amount invested
r = annual interest rate (as a decimal)
t = time period of investment (in years)
In this case, we have:
P = $9,900
r = 7.8% = 0.078 (since the rate is given as an annual rate, we need to divide by 100 to get the decimal equivalent)
t = 24 months / 12 months/year = 2 years
Substituting these values into the formula, we get:
I = 9,900 * 0.078 * 2
= $1,545.60
Therefore, the simple interest earned on the investment is $1,545.60.