The ratio of the number of wafers in Container V to the number of wafers in Container W was 5 : 3. 40% of the wafers in Container V and 0.7 of those in Container W were butter cream. After transferring the wafers between the 2 containers, the number of chocolate wafers in both containers are the same. Likewise, the number of butter cream wafers in both containers are the same. If a total of 220 wafers were moved, how many more wafers were there in Container V than Container W at first?

Container V		Container W
5 u		3 u
Butter Cream	Chocolate	Butter Cream	Chocolate
2 u	3 u	2.1 u	0.9 u
+ 0.05 u	- 1.05 u	- 0.05 u	+ 1.05 u
2.05 u	1.95 u	2.05 u	1.95 u

Number of butter cream wafers in Container V
= 40% x 5 u
= ⁴⁰₁₀₀ x 5 u
= 2 u

Number of chocolate wafers in Container V
= 5 u - 2 u
= 3 u

Number of butter cream wafers in Container W
= 0.7 x 3 u
= 2.1 u

Number of chocolate wafers in Container W
= 3 u - 2.1 u
= 0.9 u

Number of butter cream wafers in each container in the end
= (2 u + 2.1 u) ÷ 2
= 4.1 u ÷ 2
= 2.05 u

Number of chocolate wafers in each container in the end
= (3 u + 0.9 u) ÷ 2
= 3.9 u ÷ 2
= 1.95 u

Number of wafers moved
= 0.05 u + 1.05 u
= 1.1 u

1.1 u = 220

1 u = 220 ÷ 1.1 = 200

Number of more wafers in Container V than Container W at first
= 5 u - 3 u
= 2 u
= 2 x 200
= 400

Answer(s): 400