Hailey was able to sew 3 dresses in 2 1/2 hours. How many dresses could Hailey sew in 7 1/2 hours?

Answer 1

Note that 2 1/2 = 5/2.

Hailey's sewing rate is

(3 dresses)/(5/2 hours)

= 3*(2/5) = 6/5 dresses/hour.

Note that 7 1/2 = 15/2.

In 7 1/2 hours, Hailey will sew

(6/5 dresses/hour)*(15/2 hours)

= (6/5)*(15/2) dresses

= 9 dresses

Answer: 9 dresses