Three types of sugar, G, H and J come in containers of 180 g, 240 g and 360 g respectively. Containers of G, H and J are mixed together in the ratio 1 : 2 : 4 to obtain 18.9 kg of an assortment of sugar.

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

	G	H	J
Number	1 u	2 u	4 u
Value	180	240	360
Total value	180 u	480 u	1440 u

(a)
Total mass of sugar
= 180 u + 480 u + 1440 u
= 2100 u

2100 u = 18900

1 u = 18900 ÷ 2100 = 9

Total number of containers of G and H used
= 1 u + 2 u
= 3 u
= 3 x 9
= 27 

(b)
Combined weight of all the sugar in containers H and containers J
= 480 u + 1440 u
= 1920 u

Difference between the combined weight of all the sugar in containers H and containers J as compared to the sugar in containers G
= 1920 u - 180 u
= 1740 u
= 1740 x 9
= 15660 g
= 15.66 kg 

Answer(s): (a) 27; (b) 15.66 kg