Three types of bread flour, T, U and V come in containers of 120 g, 200 g and 240 g respectively. Containers of T, U and V are mixed together in the ratio 1 : 3 : 4 to obtain 8.4 kg of an assortment of bread flour.

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

	T	U	V
Number	1 u	3 u	4 u
Value	120	200	240
Total value	120 u	600 u	960 u

(a)
Total mass of bread flour
= 120 u + 600 u + 960 u
= 1680 u

1680 u = 8400

1 u = 8400 ÷ 1680 = 5

Total number of containers of T and U used
= 1 u + 3 u
= 4 u
= 4 x 5
= 20 

(b)
Combined weight of all the bread flour in containers U and containers V
= 600 u + 960 u
= 1560 u

Difference between the combined weight of all the bread flour in containers U and containers V as compared to the bread flour in containers T
= 1560 u - 120 u
= 1440 u
= 1440 x 5
= 7200 g
= 7.2 kg 

Answer(s): (a) 20; (b) 7.2 kg