You didn’t specify the amount of years. But the equation for simple interest is I= Prt. To find the simple interest she will earn in x amount of years, you must multiply 1,025 by 0.05. Then you must multiply the answer of that to the number of years you will keep the money in the savings account. After that, you will get the interest after x number of years. Equation - I = 1,025x0.05x(time in years).