A box of shortbreads cost $6 while a box of scones cost $12. Each box contained either 8 shortbreads or 7 scones. Kimberly bought the same number of shortbreads and scones. She paid $270 more for the scones. How many boxes of shortbreads did she buy?
To make the number of shortbreads and scones that Kimberly bought the same, find the LCM of 8 and 7.

LCM of 8 and 7 = 56

Cost of 1 set of 56 shortbreads
= 6 x 7
= $42

Cost of 1 set of 56 scones
= 12 x 8
= $96

Amount that Kimberly paid more for 1 set of 56 shortbreads than 1 set of 56 scones
= 96 - 42
= $54

Number of sets of $54
= 270 ÷ 54
= 5

1 set of $54 → 7 boxes of shortbreads

5 sets of $54 → 5 x 7 = 35 boxes of shortbreads

Number of boxes of shortbreads that Kimberly bought = 35

Answer(s): 35