Question

Ama wants to sew protective masks to distribute to her friends and family.  She finds an online pattern that requires the use of elastic.  1 yard = 3 feetShe has 7.5 yards of elastic in a box.  1 foot = 12 inchesIf one mask requires 14 inches of elastic, how many masks can she make?

Answer 1

She has 7.5 yards of elastic.

Each mask requires 14 in of elastic.

To calculate how many masks she can make, we have to divide the amount of elastic she has by the amount of elastic each mask requires:

`m=\frac{7.5\text{ yd}}{14\text{ in/mask}}\cdot\frac{3\text{ ft}}{1\text{ yd}}\cdot\frac{12\text{ in}}{1\text{ ft}}=(7.5\cdot3\cdot12)/(14)\text{ masks}=(270)/(14)\approx19.29`

She can make 19 masks.

NOTE: we can use the equivalencies of the units as ratios with value 1 to multiply and have the units we need for the problem.

Answer: 19 masks.