这条GRE的题，谁懂得做?

来源: 于 2014-11-15 12:36:58 [博客] [旧帖] [给我悄悄话] 本文已被阅读：次

Sandy has a husband and 2 children. She brings at
least 1 member of her family to a diner for lunch
every day. The diner offers 10 lunch specials. If no
one orders the same thing, how many different orders
can Sandy’s family make for lunch?
Indicate all possible values.

答案选项分别是45，90，120，210，720, 5040