Using only the digits from 0 to 6 , how many 5 digit codes can be constructed, if the first digit can not be 4 and no digits is used more than once ?  Pick one:
A) 1080	B) 2160	C) 777	D) 720	E) 620
code can be contain zero,(ex 0122---, 0731---)   sw, we can consider 0 at first place.   so it should be  6*6*5*4*3= 
<gadget id="calculator"> 6*6*5*4*3</gadget>
<output>2_160</output>
2160   ANSWER:2160
<result>B</result>
Using only the digits from 0 to 6 , how many 5 digit codes can be constructed, if the first digit can not be 4 and no digits is used more than once ?