Respuesta :
1) Plug the numbers into the equation for a simple interest rate. The equation is I = Prt, where P is the initial amount, r is the interest rate, and t is the time in years. 2) You have to turn the time into years, so put it over 12 (the months in a year) to turn it into a fraction for the unit of years, and plug in the equation to get I = 1200*0.81*(9/12). 3) Multiply this equation out to get 729.00, this is the answer. Answer: $729.00 interest. **TAKE THIS WITH A GRAIN OF SALT, you wrote the interest as dollars, but in this equation I assumed you meant to write it was a percent. If you did make a mistake and the 81 interest is a percent, then the math in this equation is correct. If it is an amount of money, then don’t copy it because it would be incorrect.
Answer: the simple interest rate is 9%
Step-by-step explanation:
The formula for determining simple interest is expressed as
I = PRT/100
Where
I represents interest paid on the amount invested.
P represents the principal or amount invested.
R represents interest rate
T represents the duration of the investment in years.
From the information given,
P = $1200
T = 9 months = 9/12 = 0.75 year
I = $81
Therefore,
81 = (1200 × R × 0.75)/100
81 = 900R/100 = 9R
R = 81/9
R = 9%