Three types of rice flour, W, X and Y come in containers of 160 g, 240 g and 320 g respectively. Containers of W, X and Y are mixed together in the ratio 2 : 3 : 4 to obtain 16.24 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	2 u	3 u	4 u
Value	160	240	320
Total value	320 u	720 u	1280 u

(a)
Total mass of rice flour
= 320 u + 720 u + 1280 u
= 2320 u

2320 u = 16240

1 u = 16240 ÷ 2320 = 7

Total number of containers of W and X used
= 2 u + 3 u
= 5 u
= 5 x 7
= 35 

(b)
Combined weight of all the rice flour in containers X and containers Y
= 720 u + 1280 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 - 320 u
= 1680 u
= 1680 x 7
= 11760 g
= 11.76 kg 

Answer(s): (a) 35; (b) 11.76 kg