Question

英文数学题

Each person in a group of students was identified by his or her hair colour, and asked whether he or she preferred taking classes in the morning, afternoon, or evening. The results are shown in the table below. Find the probability that a student preferred morning classes given he or she has blonde hair.

Preference Blonde Brunette Redhead
Morning 25 5 20
Afternoon 45 30 35
Evening 15 50 5

Answer 1

学生按照头发颜色备份组，并被问到他们喜欢在上午，中午或者晚上上课。结果如下表，，找出金黄色头发中喜欢上午上课的学生的概率

金发学生总数是“25+45+15”85
头发是金黄色并且喜欢上午上课的学生找blonde和morning那行，是25
所以P=25/85=5/17

希望回答对你有帮助

Answer 2

答案是： 25