Final answer:
To find the fraction of a roll of wrapping paper used on each present, divide the total amount used by the number of presents. The answer is (1/10).
Step-by-step explanation:
To find the fraction of a roll of wrapping paper used on each present, we need to divide the total amount used by the number of presents. Sara used (3/10) of a roll of wrapping paper on three presents, so to find the amount used on each present, we divide (3/10) by 3. This can be written as (3/10) ÷ 3. To divide a fraction by a whole number, we multiply the fraction by the reciprocal of the whole number. The reciprocal of 3 is 1/3, so we have (3/10) × (1/3) = 3/30. Simplifying this fraction gives us 1/10, so the answer is option a. (1/10).