Three types of sugar, E, F and G come in containers of 120 g, 160 g and 240 g respectively. Containers of E, F and G are mixed together in the ratio 2 : 5 : 7 to obtain 16.32 kg of an assortment of sugar.

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

	E	F	G
Number	2 u	5 u	7 u
Value	120	160	240
Total value	240 u	800 u	1680 u

(a)
Total mass of sugar
= 240 u + 800 u + 1680 u
= 2720 u

2720 u = 16320

1 u = 16320 ÷ 2720 = 6

Total number of containers of E and F used
= 2 u + 5 u
= 7 u
= 7 x 6
= 42 

(b)
Combined weight of all the sugar in containers F and containers G
= 800 u + 1680 u
= 2480 u

Difference between the combined weight of all the sugar in containers F and containers G as compared to the sugar in containers E
= 2480 u - 240 u
= 2240 u
= 2240 x 6
= 13440 g
= 13.44 kg 

Answer(s): (a) 42; (b) 13.44 kg