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 |
Gold |
2 |
Grey |
4 |
Red |
5 |
In each container, the number of gold balls was 20% more than the number of red balls and 50% less than the number of grey balls. Given that the total possible points if the group managed to collect all the balls were 680 points, how many balls were not gold in colour?
Gold |
Grey |
Red |
6x1 |
|
5x1 |
1x6 |
2x6 |
|
6 u |
12 u |
5 u |
|
Gold |
Grey |
Red |
Total |
Number |
6 u |
12 u |
5u |
|
Value |
2 |
4 |
5 |
|
Total value |
12 u |
48 u |
25 u |
85 u |
100% + 20% = 120%
120% =
120100 =
65 100% - 50% = 50%
50% =
50100 =
12 Total number of points collected
= 12 u + 48 u + 25 u
= 85 u
85 u = 680
1 u = 680 ÷ 85 = 8
Number of balls not grey in colour
= 6 u + 5 u
= 11 u
= 11 x 8
= 88
Answer: 88