Tina has 10 packages of yarn to knit a scarf. She uses 1/3 package of yarn for each inch of length she adds to the scarf. If Tina uses all the yarn, how long will her scarf be?

30 inches

Step-by-step 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