Tom had three bags of corn starch, G, H and J and the mass of each bag of corn starch was in the ratio 1 : 3 : 1. Tom decided to transfer 30% of corn starch from Bag G into Bag H and 70% of corn starch from Bag J into Bag H. Given that the mass of Bag H was 20 kg in the end, how many kilograms of corn starch were transferred into Bag H?

	G	H	J
Before	1 u	3 u	1 u
Change 1	- 0.3 u	+ 0.3 u
Change 2		+ 0.7 u	- 0.7 u
After	0.7 u	4 u	0.3 u

Mass of corn starch transferred from Bag G into Bag H
= 30% x 1 u
= ³⁰₁₀₀ x 1 u
= 0.7 u

Mass of corn starch transferred from Bag J into Bag H
= 70% x 1 u
= ⁷⁰₁₀₀ x 1 u
= 0.7 u

Mass of corn starch in Bag H in the end
= 3 u + 0.3 u + 0.7 u
= 4 u

4 u = 20 

1 u = 20 ÷ 4 = 5

Mass of corn starch transferred into Bag H
= 0.3 u + 0.7 u
= 1 u
= 1 x 5
= 5 kg

Answer(s): 5 kg