Three types of pepper, D, E and F come in containers of 160 g, 280 g and 400 g respectively. Containers of D, E and F are mixed together in the ratio 3 : 4 : 7 to obtain 30.8 kg of an assortment of pepper.

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

	D	E	F
Number	3 u	4 u	7 u
Value	160	280	400
Total value	480 u	1120 u	2800 u

(a)
Total mass of pepper
= 480 u + 1120 u + 2800 u
= 4400 u

4400 u = 30800

1 u = 30800 ÷ 4400 = 7

Total number of containers of D and E used
= 3 u + 4 u
= 7 u
= 7 x 7
= 49 

(b)
Combined weight of all the pepper in containers E and containers F
= 1120 u + 2800 u
= 3920 u

Difference between the combined weight of all the pepper in containers E and containers F as compared to the pepper in containers D
= 3920 u - 480 u
= 3440 u
= 3440 x 7
= 24080 g
= 24.08 kg 

Answer(s): (a) 49; (b) 24.08 kg