Question

Jacob invested $300 in a savings account and earned $81 in simple interest at the end of 9 years. what was the interest rate

Answer 1

Answer:

A.

Step-by-step explanation:

We use the simple interest equation of A=P(1+rt).

A-the total amount with interest earned

P-the initial amount or principal

r-rate

t-time in years

We substitute the values P=300, A=381, and t=9. We then solve for r.

$381=300(1+9r)$

We divide both sides by 300.

$\frac{381}{300}=\frac{300(1+9r)}{300}$

Simplify.

$1.27=1+9r$

We subtract 1 from both sides.

$1.27-1=1-1+9r$

Simplify.

$0.27=9r$

We divide by 9.

$\frac{0.27}{9}=\frac{9r}{9}$

r=0.03

We need to convert the decimal to a percentage by multiplying by 100.

The interest rate is 3%.