The ratio of the number of cupcakes in Container W to the number of cupcakes in Container X was 7 : 5. 20% of the cupcakes in Container W and 0.6 of those in Container X were mocha. After transferring the cupcakes between the 2 containers, the number of chocolate cupcakes in both containers are the same. Likewise, the number of mocha cupcakes in both containers are the same. If a total of 234 cupcakes were moved, how many more cupcakes were there in Container W than Container X at first?

Container W		Container X
7 u		5 u
Mocha	Chocolate	Mocha	Chocolate
1.4 u	5.6 u	3 u	2 u
+ 0.8 u	- 1.8 u	- 0.8 u	+ 1.8 u
2.2 u	3.8 u	2.2 u	3.8 u

Number of mocha cupcakes in Container W
= 20% x 7 u
= ²⁰₁₀₀ x 7 u
= 1.4 u

Number of chocolate cupcakes in Container W
= 7 u - 1.4 u
= 5.6 u

Number of mocha cupcakes in Container X
= 0.6 x 5 u
= 3 u

Number of chocolate cupcakes in Container X
= 5 u - 3 u
= 2 u

Number of mocha cupcakes in each container in the end
= (1.4 u + 3 u) ÷ 2
= 4.4 u ÷ 2
= 2.2 u

Number of chocolate cupcakes in each container in the end
= (5.6 u + 2 u) ÷ 2
= 7.6 u ÷ 2
= 3.8 u

Number of cupcakes moved
= 0.8 u + 1.8 u
= 2.6 u

2.6 u = 234

1 u = 234 ÷ 2.6 = 90

Number of more cupcakes in Container W than Container X at first
= 7 u - 5 u
= 2 u
= 2 x 90
= 180

Answer(s): 180