Answer:
30 inches
Explanation:
She has 10 packages of yarn.
She uses 1/3 package of yarn for each inch of the scarf.
Therefore, 1 package of yarn will be 3 times each inch:
3 * 1 = 3 inches
1 package of yarn goes for 3 inches of scarf.
Therefore, 10 packages will go for:
10 * 3 = 30 inches