Japheth had three bags of soya beans, L, M and N and the mass of each bag of soya beans was in the ratio 3 : 4 : 5. Japheth decided to transfer 30% of soya beans from Bag L into Bag M and 60% of soya beans from Bag N into Bag M. Given that the mass of Bag M was 71.1 kg in the end, how many kilograms of soya beans were transferred into Bag M?

	L	M	N
Before	3 u	4 u	5 u
Change 1	- 0.9 u	+ 0.9 u
Change 2		+ 3 u	- 3 u
After	2.1 u	7.9 u	2 u

Mass of soya beans transferred from Bag L into Bag M
= 30% x 3 u
= ³⁰₁₀₀ x 3 u
= 2.1 u

Mass of soya beans transferred from Bag N into Bag M
= 60% x 5 u
= ⁶⁰₁₀₀ x 5 u
= 3 u

Mass of soya beans in Bag M in the end
= 4 u + 0.9 u + 3 u
= 7.9 u

7.9 u = 71.1 

1 u = 71.1 ÷ 7.9 = 9

Mass of soya beans transferred into Bag M
= 0.9 u + 3 u
= 3.9 u
= 3.9 x 9
= 35.1 kg

Answer(s): 35.1 kg