Total number of ways to choose 4 shoes from 8=‌8C4=70 We want to choose 4 shoes that none of them form a pair. Firstly, choose 4 different pairs from the 4 available pairs =‌4C4=1 For each of the 4 pairs, 2 choices (left or right) =24=16. Hence, total number of ways to choose 4 shoes with no pair =1×24=16. Thus, number of ways with atleast one pair =70−16=54. ∴ Required probability =‌