Three types of flour, S, T and U come in containers of 160 g, 280 g and 400 g respectively. Containers of S, T and U are mixed together in the ratio 1 : 4 : 6 to obtain 25.76 kg of an assortment of flour.

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

	S	T	U
Number	1 u	4 u	6 u
Value	160	280	400
Total value	160 u	1120 u	2400 u

(a)
Total mass of flour
= 160 u + 1120 u + 2400 u
= 3680 u

3680 u = 25760

1 u = 25760 ÷ 3680 = 7

Total number of containers of S and T used
= 1 u + 4 u
= 5 u
= 5 x 7
= 35 

(b)
Combined weight of all the flour in containers T and containers U
= 1120 u + 2400 u
= 3520 u

Difference between the combined weight of all the flour in containers T and containers U as compared to the flour in containers S
= 3520 u - 160 u
= 3360 u
= 3360 x 7
= 23520 g
= 23.52 kg 

Answer(s): (a) 35; (b) 23.52 kg