In a stall that sells blazers, 500 blue blazers were sold and 50% of the remaining blazers that were sold were grey. Of the leftover, 40% of the blazers sold were yellow blazers and the rest were red blazers. Given that the number of red blazers sold was 10% of the total number of blazers sold, how many grey and blue blazers were sold altogether?
50% = ⁵⁰₁₀₀ = ¹₂
40% = ⁴⁰₁₀₀ = ²₅
10% = ¹⁰₁₀₀ = ¹₁₀

Blue	Grey	Yellow	Red
500	1x5	1x5
		2x1	3x1
9x3			1x3
20 u	5 u	2 u	3 u

The total number of yellow and red shirts is the combined repeated identity. Make the total number of yellow and red shirts the same. LCM of 1 and 5 is 5.

The number of red shirts is repeated. Make the number of red shirts the same. LCM of 3 and 1 is 3.

Number of blue blazers
= 27 u - 5 u - 2 u
= 20 u

20 u = 500

1 u = 500 ÷ 20 = 25

Number of grey and blue blazers
= 5 u + 500
= (5 x 25) + 500
= 125 + 500
= 625

Answer(s): 625