The ratio of the number of cookies in Container B to the number of cookies in Container C was 7 : 3. 20% of the cookies in Container B and 0.8 of those in Container C were strawberry. After transferring the cookies between the 2 containers, the number of chocolate cookies in both containers are the same. Likewise, the number of strawberry cookies in both containers are the same. If a total of 288 cookies were moved, how many more cookies were there in Container B than Container C at first?

Container B		Container C
7 u		3 u
Strawberry	Chocolate	Strawberry	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 strawberry cookies in Container B
= 20% x 7 u
= ²⁰₁₀₀ x 7 u
= 1.4 u

Number of chocolate cookies in Container B
= 7 u - 1.4 u
= 5.6 u

Number of strawberry cookies in Container C
= 0.8 x 3 u
= 2.4 u

Number of chocolate cookies in Container C
= 3 u - 2.4 u
= 0.6 u

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

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

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

3 u = 288

1 u = 288 ÷ 3 = 96

Number of more cookies in Container B than Container C at first
= 7 u - 3 u
= 4 u
= 4 x 96
= 384

Answer(s): 384