Ian borrows $3580 at 31% simple interest per year. When Ian pays the loan back 7 years later, how much interest does Ian pay?

0.31 * 7 * 3580

To calculate the amount of interest Ian pays, we first need to find the simple interest per year.

Simple interest is calculated using the formula:
Simple Interest = Principal × Rate × Time

Where:
Principal = $3580 (the amount borrowed)
Rate = 31% per year (or 0.31 as a decimal)
Time = 7 years

So, the simple interest per year is:
Simple Interest = $3580 × 0.31 × 7

Let's calculate this:

Simple Interest = $389.12 × 7

Simple Interest = $2,723.84

Therefore, Ian pays $2,723.84 in interest over the 7-year period.

To find out how much interest Ian pays, we need to calculate the simple interest on the loan.

The formula to calculate simple interest is:
I = P * r * t

Where:
I = Interest
P = Principal amount (amount borrowed)
r = Annual interest rate (in decimal form)
t = Time (in years)

In this case:
P = $3580
r = 31% = 0.31 (converted to decimal form)
t = 7 years

Now let's plug these values into the formula:

I = 3580 * 0.31 * 7

Calculating this equation:
I = $7856.60

Therefore, Ian pays $7,856.60 in interest.