In a container, there are chocolate bars of 3 colours, blue, red and green. There are 520 less green chocolate bars than red chocolate bars. The number of green chocolate bars is ¹₂ more than the blue chocolate bars. Given that the number of green chocolate bars is 18% of the total number of chocolate bars in the container, how many less blue chocolate bars are there than red chocolate bars?

Blue chocolate bars	Red chocolate bars	Green chocolate bars
	1 u + 520	1 u
2x6		3x6
82%		18%
12%	70%	18%

1 + ¹₂ = ²₂ + ¹₂ = ³₂

Yellow chocolate bars : Purple chocolate bars = 2 : 3

The number of green chocolate bars is repeated.  Make the number of green chocolate bars the same.

3 x 6 = 18%

Total number of blue chocolate bars and red chocolate bars in percent
= 100% - 18%
= 82%

Number of red chocolate bars in percent
= 82% - 12%
= 70%

Number of more red chocolate bars than green chocolate bars in percent
= 70% - 12%
= 52%

52% = 520

1% = 520 ÷ 52 = 10

Number of less blue chocolate bars than red chocolate bars
= 70% - 12%
= 58%
= 58 x 10
= 580

Answer(s): 580