Final answer:
Madelyn will have $78 in her savings account after 3 years, which includes her initial $60 principal and $18 of interest earned at a rate of 10% annually with simple interest.
Step-by-step explanation:
Madelyn has $60 in a savings account that earns 10% annually with simple interest. To calculate how much she will have in 3 years, we can use the formula i = prt, where i is the interest earned, p is the principal, r is the interest rate expressed as a decimal, and t is the time in years.
By substituting the given values into the formula, we get i = $60 × 0.10 × 3. Therefore, the interest earned will be i = $18 over the three years.
To find the total amount Madelyn will have in her savings account after 3 years, we add the interest earned to the principal. The total future amount with simple interest is therefore $60 + $18 = $78.