In a box, there are sweets of 3 colours, yellow, grey and silver. There are 402 less silver sweets than grey sweets. The number of silver sweets is ¹₃ more than the yellow sweets. Given that the number of silver sweets is 12% of the total number of sweets in the box, how many less yellow sweets are there than grey sweets?

Yellow sweets	Grey sweets	Silver sweets
	1 u + 402	1 u
3x3		4x3
88%		12%
9%	79%	12%

1 + ¹₃ = ³₃ + ¹₃ = ⁴₃

Yellow sweets : Purple sweets = 3 : 4

The number of silver sweets is repeated.  Make the number of silver sweets the same.

4 x 3 = 12%

Total number of yellow sweets and grey sweets in percent
= 100% - 12%
= 88%

Number of grey sweets in percent
= 88% - 9%
= 79%

Number of more grey sweets than silver sweets in percent
= 79% - 9%
= 67%

67% = 402

1% = 402 ÷ 67 = 6

Number of less yellow sweets than grey sweets
= 79% - 9%
= 70%
= 70 x 6
= 420

Answer(s): 420