Three types of rice flour, X, Y and Z come in containers of 160 g, 240 g and 320 g respectively. Containers of X, Y and Z are mixed together in the ratio 3 : 4 : 5 to obtain 33.44 kg of an assortment of rice flour.

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

	X	Y	Z
Number	3 u	4 u	5 u
Value	160	240	320
Total value	480 u	960 u	1600 u

(a)
Total mass of rice flour
= 480 u + 960 u + 1600 u
= 3040 u

3040 u = 33440

1 u = 33440 ÷ 3040 = 11

Total number of containers of X and Y used
= 3 u + 4 u
= 7 u
= 7 x 11
= 77 

(b)
Combined weight of all the rice flour in containers Y and containers Z
= 960 u + 1600 u
= 2560 u

Difference between the combined weight of all the rice flour in containers Y and containers Z as compared to the rice flour in containers X
= 2560 u - 480 u
= 2080 u
= 2080 x 11
= 22880 g
= 22.88 kg 

Answer(s): (a) 77; (b) 22.88 kg