In a mall that sells skirts, 638 red skirts were sold and 10% of the remaining skirts that were sold were gold. Of the leftover, 40% of the skirts sold were white skirts and the rest were black skirts. Given that the number of black skirts sold was 25% of the total number of skirts sold, how many gold and red skirts were sold altogether?
10% = ¹⁰₁₀₀ = ¹₁₀
40% = ⁴⁰₁₀₀ = ²₅
25% = ²⁵₁₀₀ = ¹₄

Red	Gold	White	Black
638	1x5	9x5
		2x9	3x9
3x27			1x27
58 u	5 u	18 u	27 u

The total number of white and black shirts is the combined repeated identity. Make the total number of white and black shirts the same. LCM of 9 and 5 is 45.

The number of black shirts is repeated. Make the number of black shirts the same. LCM of 27 and 1 is 27.

Number of red skirts
= 81 u - 5 u - 18 u
= 58 u

58 u = 638

1 u = 638 ÷ 58 = 11

Number of gold and red skirts
= 5 u + 638
= (5 x 11) + 638
= 55 + 638
= 693

Answer(s): 693