In a certain fashion house, which has four sizes of a specific shirt, there is one-third as many small shirts as medium shirts, and 1/2 as many large shirts as small shirts. If there are as many X-large shirts as large shirts, what percent of the shirts in the store are medium?

Let, the parcent of medium shirts be M. Then, the parcent of small shirts = M/3 The parcent of large shirts = (1/2) x M/3 = M/6 The parcent of X - large shirts = M/6 Now,  M = 1 - (M/3 + M/6 + M/6) = 1 - 2M/3 or,   M + 2M/3 = 1 or,   5M/3 = 1 or,   M = 3/5 So,   M = (3/5) x 100% = 60%