Elijah had three bags of soya beans, X, Y and Z and the mass of each bag of soya beans was in the ratio 2 : 1 : 1. Elijah decided to transfer 20% of soya beans from Bag X into Bag Y and 60% of soya beans from Bag Z into Bag Y. Given that the mass of Bag Y was 12 kg in the end, how many kilograms of soya beans were transferred into Bag Y?

	X	Y	Z
Before	2 u	1 u	1 u
Change 1	- 0.4 u	+ 0.4 u
Change 2		+ 0.6 u	- 0.6 u
After	1.6 u	2 u	0.4 u

Mass of soya beans transferred from Bag X into Bag Y
= 20% x 2 u
= ²⁰₁₀₀ x 2 u
= 1.6 u

Mass of soya beans transferred from Bag Z into Bag Y
= 60% x 1 u
= ⁶⁰₁₀₀ x 1 u
= 0.6 u

Mass of soya beans in Bag Y in the end
= 1 u + 0.4 u + 0.6 u
= 2 u

2 u = 12 

1 u = 12 ÷ 2 = 6

Mass of soya beans transferred into Bag Y
= 0.4 u + 0.6 u
= 1 u
= 1 x 6
= 6 kg

Answer(s): 6 kg