Kimberly and Irene used the same number of chocolate chips to bake cakes. Kimberly used ⁴₅ of her chocolate chips and Irene used ³₇ of her chocolate chips. They had a total of 172 chocolate chips at first.

1. How many chocolate chips did each girl use?
2. How many chocolate chips did both girls have left altogether?

	Kimberly	Irene	Total
Before	5x3 = 15 u	7x4 = 28 u	43 u
Change	- 4x3 = - 12 u	- 3x4 = - 12 u
After	1x3 = 3 u	4x4 = 16 u	19 u

(a)
Kimberly and Irene used the same number of chocolate chips to bake cakes.  Make the numerators the same. LCM of 4 and 3 is 12. 
4x35x3 of Mary's chocolate chips = 3x47x4 of Irene's chocolate chips 
1215 of Mary's chocolate chips = 1228 of Irene's chocolate chips 

Total number of chocolate chips at first
= 15 u + 28 u
= 43 u

43 u = 172

1 u = 172 ÷ 43 = 4

Number of chocolate chips that each girl used
= 12 u
= 12 x 4
= 48 

(b)
Total number of chocolate chips that both girls had left 
= 3 u + 16 u
= 19 u
= 19 x 4
= 76

Answer(s): (a) 48; (b) 76