Oscar had three bags of corn starch, B, C and D and the mass of each bag of corn starch was in the ratio 5 : 4 : 2. Oscar decided to transfer 40% of corn starch from Bag B into Bag C and 80% of corn starch from Bag D into Bag C. Given that the mass of Bag C was 76 kg in the end, how many kilograms of corn starch were transferred into Bag C?

	B	C	D
Before	5 u	4 u	2 u
Change 1	- 2 u	+ 2 u
Change 2		+ 1.6 u	- 1.6 u
After	3 u	7.6 u	0.4 u

Mass of corn starch transferred from Bag B into Bag C
= 40% x 5 u
= ⁴⁰₁₀₀ x 5 u
= 3 u

Mass of corn starch transferred from Bag D into Bag C
= 80% x 2 u
= ⁸⁰₁₀₀ x 2 u
= 1.6 u

Mass of corn starch in Bag C in the end
= 4 u + 2 u + 1.6 u
= 7.6 u

7.6 u = 76 

1 u = 76 ÷ 7.6 = 10

Mass of corn starch transferred into Bag C
= 2 u + 1.6 u
= 3.6 u
= 3.6 x 10
= 36 kg

Answer(s): 36 kg