In a box, there are chocolate bars of 3 colours, yellow, green and black. There are 580 less black chocolate bars than green chocolate bars. The number of black chocolate bars is ¹₄ more than the yellow chocolate bars. Given that the number of black chocolate bars is 15% of the total number of chocolate bars in the box, how many less yellow chocolate bars are there than green chocolate bars?

Yellow chocolate bars	Green chocolate bars	Black chocolate bars
	1 u + 580	1 u
4x3		5x3
85%		15%
12%	73%	15%

1 + ¹₄ = ⁴₄ + ¹₄ = ⁵₄

Yellow chocolate bars : Purple chocolate bars = 4 : 5

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

5 x 3 = 15%

Total number of yellow chocolate bars and green chocolate bars in percent
= 100% - 15%
= 85%

Number of green chocolate bars in percent
= 85% - 12%
= 73%

Number of more green chocolate bars than black chocolate bars in percent
= 73% - 12%
= 58%

58% = 580

1% = 580 ÷ 58 = 10

Number of less yellow chocolate bars than green chocolate bars
= 73% - 12%
= 61%
= 61 x 10
= 610

Answer(s): 610