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

Colours	Points
Gold	2
Red	4
White	7

In each container, the number of gold marbles was 80% more than the number of white marbles and 90% less than the number of red marbles. Given that the total possible points if the group managed to collect all the marbles were 2891 points, how many marbles were not gold in colour?

Gold	Red	White
9x1		5x1
1x9	10x9
9 u	90 u	5 u

	Gold	Red	White	Total
Number	9 u	90 u	5u
Value	2	4	7
Total value	18 u	360 u	35 u	413 u

100% + 80% = 180%
180% = ¹⁸⁰₁₀₀ =⁹₅

100% - 90% = 10%
10% = ¹⁰₁₀₀ = ¹₁₀

Total number of points collected
= 18 u + 360 u + 35 u
= 413 u

413 u = 2891

1 u = 2891 ÷ 413 = 7

Number of marbles not gold in colour
= 90 u + 5 u
= 95 u
= 95 x 7
= 665

Answer: 665