J4 ›› 2011, Vol. 10 ›› Issue (4): 96-100.
This paper mainly inquires into and analyzes va~ous solutions to question 20 of mathematics in 2010 College Entrance Examination(national volume II)for science students．By showing various solutions to this question，the paper elaborates how to solve such questions of probability statistics，and provides a useful reference to college entrance examination for students．
