a. How many different 7-place license plates are possible if the first 2 places are for letters and the other 5 for numbers?
b. Repeat part (a) under the assumption that no letter or number can be repeated in a single license plate.
(a)
The number of different 7-place license plates.
67600000
Given:
First 2 places are for letters.
Other 5 places are for numbers.
Calculation:
Total number of letters is 26 (A to Z)
Total number of digits is 10 (0 to 9)
Applying the basic principle of counting, number of license plates will be
(b)
The number of different 7-place license plates.
19656000
Given:
First 2 places are for letters.
Other 5 places are for numbers.
No letter or number can be repeated in a single license plate.
Calculation:
As there can be no repetition,
The first place letter has 26 options.
The second place letter has 25 options.
The third place digit has 10 options.
The fourth place digit has 9 options.
The fifth place digit has 8 options.
The sixth place digit has 7 options.
The seventh place digit has 6 options.
Applying the basic principle of counting, number of license plates will be