3 because Negative numbers equal less than 0. See the number line attached below. In the number line, all the negative numbers are on the left of the zero and all the positive numbers are on the right of the 0.
Noo........................b
Given:
Interest = 4,275
interest rate = 2.5%
term = 18 years
Principal = ?
Interest = Principal * interest rate * term
4,275 = P * 2.5% * 18
4,275/ (2.5% * 18) = P
4,275 / 0.45 = P
9,500 = P
Your mom deposited 9,500 when you were born.