Question

coral invested $500 in an account that earns simple interest at the rate of %5.5 each year. Assuming coral does not invest anymore money it will take how many years for coral to have %720 in her account?

Answer 1

Answer:

The number of years it will take coral to have $720 in her account is 8 years

Step-by-step explanation:

The principal amount coral invested, P = $500

The simple interest rate earned per year, r = 5.5%

The amount in coral account after t years, A = $720

The formula for simple interest is given as follows;

$Simple \ Interest, \ SI = \dfrac{Principal, P \times Rate, r \times Time, t}{100}$

The formula for amount, A = SI + P

Therefore, we have;

$A = \dfrac{P \times r \times t}{100} + P$

$720 = \dfrac{500 \times 5.5 \times t}{100} + 500$

$720 - 500 = \dfrac{500 \times 5.5 \times t}{100}$

$220 = \dfrac{500 \times 5.5 \times t}{100}$

22000 = 500 × 5.5 × t

t = 22000/(500 × 5.5) = 8

The number of years, t, it will take coral to have $720 in her account = 8 years.