To calculate the interest on an account, we can use the formula: Interest = Principal x Rate x Time.
In this case, the principal (amount invested) is $580, the rate is 7½% (or 0.075 as a decimal), and the time is 3 years.
Using the formula, we can calculate the interest as follows:
Interest = $580 x 0.075 x 3 = $123.75
Therefore, the amount of interest on the account would be $123.75.