Question

Ernie Rolph borrowed ​$3200 at 10​% annual simple interest. If exactly 1 year later he was able to repay the loan without​ penalty, how much interest would he​ owe?

Answer 1

$320

Explanation:

From simple interest formular

A=P(1+int) where A is amount payable, P is principal amount borrowed and int is interest gained

int=Rt where R is rate of interest in decimal form, t is duration

The rate of 10% converted to decimal is 10/100=0.1

Substituting P for $3200, R for 0.1 and t for 1 year

A=$3200(1+(0.1*1))=$3200*(1+0.1)=3200*1.1=$3520

To find the interest, it's A-P hence $3520-$3200=$320

Therefore, interest owed is $320