[問題]GWD12-19

[brucechiang]

Dear All: Please help me to solve this question.
Q19. How many 4-digit positive integers are there in which all 4 digits are even?

A. 625
B. 600
C. 500
D. 400
E. 256

Ans: C

Thanks in advance

[kwtluck]

4個數字都要是偶數, 所以每個數有5種選擇:0,2,4,6,8
但千位數不可以是"0"=>四種選擇
個,十,百位數=>五種選擇
所以4*5*5*5=500

**歡迎你啊!!新同學~~**

[brucechiang]

Hi~Kwtluck:
Thanks so much Meanwhile, I wonder why I have never considered "0" as one factor of even....

Thanks again!