The ratio of the number of wafers in Container W to the number of wafers in Container X was 7 : 3. 20% of the wafers in Container W and 0.8 of those in Container X were vanilla. After transferring the wafers between the 2 containers, the number of chocolate wafers in both containers are the same. Likewise, the number of vanilla wafers in both containers are the same. If a total of 192 wafers were moved, how many more wafers were there in Container W than Container X at first?

Container W		Container X
7 u		3 u
Vanilla	Chocolate	Vanilla	Chocolate
1.4 u	5.6 u	2.4 u	0.6 u
+ 0.5 u	- 2.5 u	- 0.5 u	+ 2.5 u
1.9 u	3.1 u	1.9 u	3.1 u

Number of vanilla wafers in Container W
= 20% x 7 u
= ²⁰₁₀₀ x 7 u
= 1.4 u

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

Number of vanilla wafers in Container X
= 0.8 x 3 u
= 2.4 u

Number of chocolate wafers in Container X
= 3 u - 2.4 u
= 0.6 u

Number of vanilla wafers in each container in the end
= (1.4 u + 2.4 u) ÷ 2
= 3.8 u ÷ 2
= 1.9 u

Number of chocolate wafers in each container in the end
= (5.6 u + 0.6 u) ÷ 2
= 6.2 u ÷ 2
= 3.1 u

Number of wafers moved
= 0.5 u + 2.5 u
= 3 u

3 u = 192

1 u = 192 ÷ 3 = 64

Number of more wafers in Container W than Container X at first
= 7 u - 3 u
= 4 u
= 4 x 64
= 256

Answer(s): 256