Sarah bought 8 folders and 3 rulers. Lea bought 8 rulers and 3 folders. Sarah paid $1.25 more than
Lea. How much was each folder if each ruler was 45₵?
8f + 3(45) = 3f + 8(45) + 125
f = 70 ¢
8 f + 3 r = 1.25 + 8 r + 3 f
but r = 0.45
8 f + 1.35 = 1.25 + 3.60 + 3 f
5 f = 3.50
f = 0.70 or 70 cents