Three types of bread flour, X, Y and Z come in containers of 150 g, 250 g and 400 g respectively. Containers of X, Y and Z are mixed together in the ratio 2 : 5 : 6 to obtain 19.75 kg of an assortment of bread flour.

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

	X	Y	Z
Number	2 u	5 u	6 u
Value	150	250	400
Total value	300 u	1250 u	2400 u

(a)
Total mass of bread flour
= 300 u + 1250 u + 2400 u
= 3950 u

3950 u = 19750

1 u = 19750 ÷ 3950 = 5

Total number of containers of X and Y used
= 2 u + 5 u
= 7 u
= 7 x 5
= 35 

(b)
Combined weight of all the bread flour in containers Y and containers Z
= 1250 u + 2400 u
= 3650 u

Difference between the combined weight of all the bread flour in containers Y and containers Z as compared to the bread flour in containers X
= 3650 u - 300 u
= 3350 u
= 3350 x 5
= 16750 g
= 16.75 kg 

Answer(s): (a) 35; (b) 16.75 kg