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

Colours	Points
Purple	2
White	5
Pink	7

In each container, the number of purple balls was 80% more than the number of pink balls and 50% less than the number of white balls. Given that the total possible points if the group managed to collect all the balls were 715 points, how many balls were not purple in colour?

Purple	White	Pink
9x1		5x1
1x9	2x9
9 u	18 u	5 u

	Purple	White	Pink	Total
Number	9 u	18 u	5u
Value	2	5	7
Total value	18 u	90 u	35 u	143 u

100% + 80% = 180%
180% = ¹⁸⁰₁₀₀ =⁹₅

100% - 50% = 50%
50% = ⁵⁰₁₀₀ = ¹₂

Total number of points collected
= 18 u + 90 u + 35 u
= 143 u

143 u = 715

1 u = 715 ÷ 143 = 5

Number of balls not purple in colour
= 18 u + 5 u
= 23 u
= 23 x 5
= 115

Answer: 115