Three types of sugar, U, V and W come in containers of 120 g, 300 g and 360 g respectively. Containers of U, V and W are mixed together in the ratio 3 : 4 : 5 to obtain 20.16 kg of an assortment of sugar.

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

	U	V	W
Number	3 u	4 u	5 u
Value	120	300	360
Total value	360 u	1200 u	1800 u

(a)
Total mass of sugar
= 360 u + 1200 u + 1800 u
= 3360 u

3360 u = 20160

1 u = 20160 ÷ 3360 = 6

Total number of containers of U and V used
= 3 u + 4 u
= 7 u
= 7 x 6
= 42 

(b)
Combined weight of all the sugar in containers V and containers W
= 1200 u + 1800 u
= 3000 u

Difference between the combined weight of all the sugar in containers V and containers W as compared to the sugar in containers U
= 3000 u - 360 u
= 2640 u
= 2640 x 6
= 15840 g
= 15.84 kg 

Answer(s): (a) 42; (b) 15.84 kg