Three types of rice flour, B, C and D come in containers of 150 g, 200 g and 350 g respectively. Containers of B, C and D are mixed together in the ratio 2 : 4 : 7 to obtain 35.5 kg of an assortment of rice flour.

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

	B	C	D
Number	2 u	4 u	7 u
Value	150	200	350
Total value	300 u	800 u	2450 u

(a)
Total mass of rice flour
= 300 u + 800 u + 2450 u
= 3550 u

3550 u = 35500

1 u = 35500 ÷ 3550 = 10

Total number of containers of B and C used
= 2 u + 4 u
= 6 u
= 6 x 10
= 60 

(b)
Combined weight of all the rice flour in containers C and containers D
= 800 u + 2450 u
= 3250 u

Difference between the combined weight of all the rice flour in containers C and containers D as compared to the rice flour in containers B
= 3250 u - 300 u
= 2950 u
= 2950 x 10
= 29500 g
= 29.5 kg 

Answer(s): (a) 60; (b) 29.5 kg