Question

Maria invested $450 in a savings account and earned $126 in interest at the end of 7 years.

What was the interest rate?

A.
3.5%

B.
4%

C.
4.5%

D.
5%

Answer 1

Interest = principal * interest rate expressed as a decimal * time in years.
$126 = $450 * X * 7. Now multiply $450 * 7 years = $3,150
$126 = 3,150X

What has been done to the X? It was multiplied by $3,150. What is the opposite of multiplication? It is division. Remember that whatever we do to one side of the equal sign we must also do to the other side of the equal sign.

$126 = $3,150X
-------____----------
$3,150__$3,150

Any number over itself = 1. Now we have
.04 = X

To change a decimal to a percent move the decimal place two places to the right and add a percent sign.
.04 = 4$. The answer is...????

Answer 2

Be honest and tell me if you don't get it....

Answer 3

B 4% right?

Answer 4

correct!