How many four digit even numbers do not use any digit more than once  Choose the correct option.
A) 1720
B) 2160
C) None of these
D) 2460
E) 2520
The Way i solved it is   A B None of these D ( thousand , hundreds, tens, units)   D can be 0 2 4 6 8 ( any of the 5 digits )   A can be anything except (D or 0) so 8 possibilities   None of these can be anything execpt A and B so 8 possibilities   B can be anything execpt ( A D None of these ) so 7 possibilities   total ways are   8 * 7 * 8 * 5= 
<gadget id="calculator">  8 * 7 * 8 * 5</gadget>
<output>2_240</output>
2240   Ans : None of these
<result>C</result>
How many four digit even numbers do not use any digit more than once