Three types of rice flour, W, X and Y come in containers of 120 g, 160 g and 200 g respectively. Containers of W, X and Y are mixed together in the ratio 3 : 5 : 6 to obtain 28.32 kg of an assortment of rice flour.

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

	W	X	Y
Number	3 u	5 u	6 u
Value	120	160	200
Total value	360 u	800 u	1200 u

(a)
Total mass of rice flour
= 360 u + 800 u + 1200 u
= 2360 u

2360 u = 28320

1 u = 28320 ÷ 2360 = 12

Total number of containers of W and X used
= 3 u + 5 u
= 8 u
= 8 x 12
= 96 

(b)
Combined weight of all the rice flour in containers X and containers Y
= 800 u + 1200 u
= 2000 u

Difference between the combined weight of all the rice flour in containers X and containers Y as compared to the rice flour in containers W
= 2000 u - 360 u
= 1640 u
= 1640 x 12
= 19680 g
= 19.68 kg 

Answer(s): (a) 96; (b) 19.68 kg