The Adidas purchase was 1/5 that of Skechers, therefore the Skechers cost 5 * 600 = 3000 dollars.
Spending three times the cost of Adidas on Nike sneakers translates to 3 * 600 = <<3*600=1800>>1800 dollars.
All together, the three athletic-sneaker purchases cost Mimi 600 + 1800 + 3000 = <<600+1800+3000=5400>>5400 dollars.
Subtracting the amount spent on athletic sneakers from the total spent gives 8000 - 5400 = <<8000-5400=2600>>2600 dollars.
Mimi therefore spent 2600 dollars on clothes.
#### 2600