Carl had three bags of ground pepper, W, X and Y and the mass of each bag of ground pepper was in the ratio 5 : 2 : 5. Carl decided to transfer 20% of ground pepper from Bag W into Bag X and 60% of ground pepper from Bag Y into Bag X. Given that the mass of Bag X was 12 kg in the end, how many kilograms of ground pepper were transferred into Bag X?

	W	X	Y
Before	5 u	2 u	5 u
Change 1	- 1 u	+ 1 u
Change 2		+ 3 u	- 3 u
After	4 u	6 u	2 u

Mass of ground pepper transferred from Bag W into Bag X
= 20% x 5 u
= ²⁰₁₀₀ x 5 u
= 4 u

Mass of ground pepper transferred from Bag Y into Bag X
= 60% x 5 u
= ⁶⁰₁₀₀ x 5 u
= 3 u

Mass of ground pepper in Bag X in the end
= 2 u + 1 u + 3 u
= 6 u

6 u = 12 

1 u = 12 ÷ 6 = 2

Mass of ground pepper transferred into Bag X
= 1 u + 3 u
= 4 u
= 4 x 2
= 8 kg

Answer(s): 8 kg