Answer:
610 feet
Step-by-step explanation:
From the question :
1 scarf = 2.5 yards of yarn
84 scarves = x yards
Cross Multiply
1 scarf × x yards = 84 × 2.5 yards
x yards = 210 yards
Hence, 84 scarves require 210 yards
Converting yards to feet
1 yard = 3 feet
210 yards = x feet
x feet × 1 yard = 210 yards × 3 feet
x feet = 210 yards × 3 feet/1 yards
x feet = 610 feet
Hence, if Janet wants to make 84 scarves, she need to buy 610 feet of yarn