The ratio of the number of cookies in Container D to the number of cookies in Container E was 5 : 3. 30% of the cookies in Container D and 0.7 of those in Container E were peach. After transferring the cookies between the 2 boxes, the number of butter cream cookies in both boxes are the same. Likewise, the number of peach cookies in both boxes are the same. If a total of 256 cookies were moved, how many more cookies were there in Container D than Container E at first?

Container D		Container E
5 u		3 u
Peach	Butter Cream	Peach	Butter Cream
1.5 u	3.5 u	2.1 u	0.9 u
+ 0.3 u	- 1.3 u	- 0.3 u	+ 1.3 u
1.8 u	2.2 u	1.8 u	2.2 u

Number of peach cookies in Container D
= 30% x 5 u
= ³⁰₁₀₀ x 5 u
= 1.5 u

Number of butter cream cookies in Container D
= 5 u - 1.5 u
= 3.5 u

Number of peach cookies in Container E
= 0.7 x 3 u
= 2.1 u

Number of butter cream cookies in Container E
= 3 u - 2.1 u
= 0.9 u

Number of peach cookies in each box in the end
= (1.5 u + 2.1 u) ÷ 2
= 3.6 u ÷ 2
= 1.8 u

Number of butter cream cookies in each box in the end
= (3.5 u + 0.9 u) ÷ 2
= 4.4 u ÷ 2
= 2.2 u

Number of cookies moved
= 0.3 u + 1.3 u
= 1.6 u

1.6 u = 256

1 u = 256 ÷ 1.6 = 160

Number of more cookies in Container D than Container E at first
= 5 u - 3 u
= 2 u
= 2 x 160
= 320

Answer(s): 320