问题详情

Your sock drawer contains ten pairs of white socks and ten pairs of black socks. If you’re only allowed to take one sock from the drawer at a time and you can’t see the color of the sock you’re taking until you’ve taken it, how many socks do you have to take before you’re guaranteed to have at least one matching pair？ 请帮忙给出正确答案和分析，谢谢！