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
Yellow	3
Red	5
Purple	8

In each container, the number of yellow balls was 40% more than the number of purple balls and 90% less than the number of red balls. Given that the total possible points if the group managed to collect all the balls were 2877 points, how many balls were not yellow in colour?

Yellow	Red	Purple
7x1		5x1
1x7	10x7
7 u	70 u	5 u

	Yellow	Red	Purple	Total
Number	7 u	70 u	5u
Value	3	5	8
Total value	21 u	350 u	40 u	411 u

100% + 40% = 140%
140% = ¹⁴⁰₁₀₀ =⁷₅

100% - 90% = 10%
10% = ¹⁰₁₀₀ = ¹₁₀

Total number of points collected
= 21 u + 350 u + 40 u
= 411 u

411 u = 2877

1 u = 2877 ÷ 411 = 7

Number of balls not yellow in colour
= 70 u + 5 u
= 75 u
= 75 x 7
= 525

Answer: 525