The ratio of the number of puffs in Container X to the number of puffs in Container Y was 7 : 5. 10% of the puffs in Container X and 0.6 of those in Container Y were butter cream. After transferring the puffs between the 2 boxes, the number of chocolate puffs in both boxes are the same. Likewise, the number of butter cream puffs in both boxes are the same. If a total of 264 puffs were moved, how many more puffs were there in Container X than Container Y at first?

Container X		Container Y
7 u		5 u
Butter Cream	Chocolate	Butter Cream	Chocolate
0.7 u	6.3 u	3 u	2 u
+ 1.15 u	- 2.15 u	- 1.15 u	+ 2.15 u
1.85 u	4.15 u	1.85 u	4.15 u

Number of butter cream puffs in Container X
= 10% x 7 u
= ¹⁰₁₀₀ x 7 u
= 0.7 u

Number of chocolate puffs in Container X
= 7 u - 0.7 u
= 6.3 u

Number of butter cream puffs in Container Y
= 0.6 x 5 u
= 3 u

Number of chocolate puffs in Container Y
= 5 u - 3 u
= 2 u

Number of butter cream puffs in each box in the end
= (0.7 u + 3 u) ÷ 2
= 3.7 u ÷ 2
= 1.85 u

Number of chocolate puffs in each box in the end
= (6.3 u + 2 u) ÷ 2
= 8.3 u ÷ 2
= 4.15 u

Number of puffs moved
= 1.15 u + 2.15 u
= 3.3 u

3.3 u = 264

1 u = 264 ÷ 3.3 = 80

Number of more puffs in Container X than Container Y at first
= 7 u - 5 u
= 2 u
= 2 x 80
= 160

Answer(s): 160