Three types of flour, G, H and J come in containers of 90 g, 150 g and 180 g respectively. Containers of G, H and J are mixed together in the ratio 3 : 4 : 7 to obtain 10.65 kg of an assortment of flour.

1. How many containers of G and H are used altogether?
2. Find the difference between the combined weight of all the flour in containers H and containers J as compared to the flour in containers G. Express the weight in kilograms.

	G	H	J
Number	3 u	4 u	7 u
Value	90	150	180
Total value	270 u	600 u	1260 u

(a)
Total mass of flour
= 270 u + 600 u + 1260 u
= 2130 u

2130 u = 10650

1 u = 10650 ÷ 2130 = 5

Total number of containers of G and H used
= 3 u + 4 u
= 7 u
= 7 x 5
= 35 

(b)
Combined weight of all the flour in containers H and containers J
= 600 u + 1260 u
= 1860 u

Difference between the combined weight of all the flour in containers H and containers J as compared to the flour in containers G
= 1860 u - 270 u
= 1590 u
= 1590 x 5
= 7950 g
= 7.95 kg 

Answer(s): (a) 35; (b) 7.95 kg