Igor was both the 15th highest and the 15th lowest in a tennis tournament. How many people were in the tournament?
A：28
B：29
C：30
D：31
E：32

答案：B
思路：正數(shù)第十五加上倒數(shù)第十五個，應(yīng)該是30個人，但是正數(shù)和倒數(shù)的第十五名都是一個人，所以，答案應(yīng)該是29個人。