the simple interst on $480 after 2 years is $72. the rate percent per annum is

I = PRT

72 = 480 * R * 2

72 = 960R

72 / 960 = R

0.075 = 7.5% = R

To find the rate percent per annum, we can use the formula for simple interest:

Simple Interest = (Principal Amount × Rate × Time)/100

We are given that the principal amount is $480, the time is 2 years, and the simple interest is $72. Plugging these values into the formula, we get:

72 = (480 × Rate × 2) / 100

Multiplying both sides by 100:

7200 = 960 × Rate

Dividing both sides by 960:

7200 / 960 = Rate

Simplifying:

7.5 = Rate

So, the rate percent per annum is 7.5%.

To determine the rate per cent per annum, we can use the formula for simple interest:

Simple Interest = (Principal * Rate * Time) / 100

Given that the principal amount is $480 and the simple interest after 2 years is $72, we can plug these values into the formula and solve for the rate.

$72 = ($480 * Rate * 2) / 100

To find the rate, we can rearrange the formula:

Rate = ($72 * 100) / ($480 * 2)

Simplifying this equation, we get:

Rate = 15

Therefore, the rate percent per annum is 15%.