During a telematch, each group of pupils was supposed to collect as many coloured balls as possible. Each colour represented a certain point as tabulated:

Colours	Points
Black	3
Red	5
Yellow	6

In each container, the number of black balls was 80% more than the number of yellow balls and 30% less than the number of red balls. Given that the total possible points if the group managed to collect all the balls were 3396 points, how many balls were not black in colour?

Black	Red	Yellow
9x7		5x7
7x9	10x9
63 u	90 u	35 u

	Black	Red	Yellow	Total
Number	63 u	90 u	35u
Value	3	5	6
Total value	189 u	450 u	210 u	849 u

100% + 80% = 180%
180% = ¹⁸⁰₁₀₀ =⁹₅

100% - 30% = 70%
70% = ⁷⁰₁₀₀ = ⁷₁₀

Total number of points collected
= 189 u + 450 u + 210 u
= 849 u

849 u = 3396

1 u = 3396 ÷ 849 = 4

Number of balls not black in colour
= 90 u + 35 u
= 125 u
= 125 x 4
= 500

Answer: 500