Question

In a certain state, license plates each consist of 2 letters followed by either 3 or 4 digits. How many differen license plates are there that have no repeated letters or digits?

Answer 1

Answer:

26 × 26 × 10 × 10 × 10 = 676 , 000  possibilities

Step-by-step explanation:

There is nothing stating that the letters and numbers can't be repeated, so all  26  letters of the alphabet and all  10

digits can be used again.

If the first is A, we have  26  possibilities:

AA, AB, AC,AD,AE ...................................... AW, AX, AY, AZ.

If the first is B, we have  26  possibilities:

BA, BB, BC, BD, BE .........................................BW, BX,BY,BZ

And so on for every letter of the alphabet.  There are  26  choices for the  first letter and  26  choices for the second letter. The number of different combinations of  2  letters is: 26 × 26 = 676

The same applies for the three digits. There are  10  choices for the first,  10

for the second and  10  for the third:

10 × 10 × 10 = 1000  

So for a license plate which has  2  letters and  3  digits, there are:  26 × 26 ×  10 × 10 × 10 = 676 , 000  possibilities.

Hope this helps.