Hi there! To solve this question, we can just simply multiply 3 1/8 and 5, because we're looking for the total length of the board, before it was cut into 5 equal pieces. To multiply fractions, just do it straight across. Numerator * numerator / denominator * denominator. 3 1/8 as a mixed number is 25/8 and 25/8 * 5/1 is 125/8 or 15 5/8 in mixed number form. There. The board was 15 5/8 inches long. The answer is D.