Harry had three bags of ground pepper, C, D and E and the mass of each bag of ground pepper was in the ratio 4 : 2 : 5. Harry decided to transfer 30% of ground pepper from Bag C into Bag D and 90% of ground pepper from Bag E into Bag D. Given that the mass of Bag D was 69.3 kg in the end, how many kilograms of ground pepper were transferred into Bag D?

	C	D	E
Before	4 u	2 u	5 u
Change 1	- 1.2 u	+ 1.2 u
Change 2		+ 4.5 u	- 4.5 u
After	2.8 u	7.7 u	0.5 u

Mass of ground pepper transferred from Bag C into Bag D
= 30% x 4 u
= ³⁰₁₀₀ x 4 u
= 2.8 u

Mass of ground pepper transferred from Bag E into Bag D
= 90% x 5 u
= ⁹⁰₁₀₀ x 5 u
= 4.5 u

Mass of ground pepper in Bag D in the end
= 2 u + 1.2 u + 4.5 u
= 7.7 u

7.7 u = 69.3 

1 u = 69.3 ÷ 7.7 = 9

Mass of ground pepper transferred into Bag D
= 1.2 u + 4.5 u
= 5.7 u
= 5.7 x 9
= 51.3 kg

Answer(s): 51.3 kg