How many four digit numbers can be formed using the digits {1, 3, 4, 5, 7,9}(repetition of digits is not allowed)?  Choose the correct choice:
A) 360
B) 88
C) 77
D) 121
E) 123
The given digits are six.   The number of four digit numbers that can be formed using six digits is ⁶P₄ = 6 * 5 * 4 * 3= 
<gadget id="calculator">6 * 5 * 4 * 3</gadget>
<output>360</output>
360.   360nswer: 360
<result>A</result>
How many four digit numbers can be formed using the digits {1, 3, 4, 5, 7,9}(repetition of digits is not allowed)?