Jon S. answered 05/13/21
Patient and Knowledgeable Math and English Tutor
There are 26 letters and 10 digits available to begin with. If there are no repetitions then:
There are 26 letter available for the first letter
25 letters available for the 2nd letter
There are 10, 9, 8 and 7 numbers available for the next 4 digits
There are 24 letters available for the last letter.
Based on the counting principle there are 26 * 25 * 10 * 9 * 8 * 7 * 24 = 78,624,000 (D) combinations.
Tia G.
thank you! this helped05/13/21
Tom K.
Jon's answer is correct. We can also write this as P(26,3)*P(10,4), where P indicates permutation.05/13/21