Xandra and Esther used the same number of chocolate chips to bake cakes. Xandra used ⁴₇ of her chocolate chips and Esther used ³₇ of her chocolate chips. They had a total of 196 chocolate chips at first.

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

	Xandra	Esther	Total
Before	7x3 = 21 u	7x4 = 28 u	49 u
Change	- 4x3 = - 12 u	- 3x4 = - 12 u
After	3x3 = 9 u	4x4 = 16 u	25 u

(a)
Xandra and Esther used the same number of chocolate chips to bake cakes.  Make the numerators the same. LCM of 4 and 3 is 12. 
4x37x3 of Mary's chocolate chips = 3x47x4 of Esther's chocolate chips 
1221 of Mary's chocolate chips = 1228 of Esther's chocolate chips 

Total number of chocolate chips at first
= 21 u + 28 u
= 49 u

49 u = 196

1 u = 196 ÷ 49 = 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 
= 9 u + 16 u
= 25 u
= 25 x 4
= 100

Answer(s): (a) 48; (b) 100