Three types of rice flour, A, B and C come in containers of 160 g, 280 g and 360 g respectively. Containers of A, B and C are mixed together in the ratio 3 : 5 : 8 to obtain 42.84 kg of an assortment of rice flour.

1. How many containers of A and B are used altogether?
2. Find the difference between the combined weight of all the rice flour in containers B and containers C as compared to the rice flour in containers A. Express the weight in kilograms.

	A	B	C
Number	3 u	5 u	8 u
Value	160	280	360
Total value	480 u	1400 u	2880 u

(a)
Total mass of rice flour
= 480 u + 1400 u + 2880 u
= 4760 u

4760 u = 42840

1 u = 42840 ÷ 4760 = 9

Total number of containers of A and B used
= 3 u + 5 u
= 8 u
= 8 x 9
= 72 

(b)
Combined weight of all the rice flour in containers B and containers C
= 1400 u + 2880 u
= 4280 u

Difference between the combined weight of all the rice flour in containers B and containers C as compared to the rice flour in containers A
= 4280 u - 480 u
= 3800 u
= 3800 x 9
= 34200 g
= 34.2 kg 

Answer(s): (a) 72; (b) 34.2 kg