Question

SAT数学求解！

Meredith has a red hat, a blue hat, and a white hat. She also has three sweaters- one red, one blue, and on white-and three pairs of jeans-one red,one blue, and one white. Meredith wants to wear a red, white, and blue outfit consisting of one hat, one sweater,and one pair of jeans.How many different possibilities does she have?
答案是6？
怎么算出来的?

Answer 1

从hat中三种颜色，随便跳出一个，三种选法；从sweater其他二种颜色中，随便跳出一个，两种选法；最后，jean只有一种颜色可以选择了，一种选法。这是排列问题

3*2*1=6

Answer 2

分为三步，第一步，在帽子里选一种颜色，总共3 种；第二步，在毛衣里选另一种颜色，有2中；最后，在裤子里选最后一种颜色，有一种。总共3*2*1=6