Home > Practice > Arithmetic Aptitude > Permutations and Combinations > Miscellaneous
1. Find the total number of distinct vehicle numbers that can be formed using two letters followed by two numbers. Letters need to be distinct.
Coming to numbers part, there are 10 ways (any number from 0 to 9 can be chosen) to choose the first digit and similarly another 10 ways to choose the second digit.
Hence, there are totally 10 × 10 = 100 ways.
Combined with letters there are,
26P2 × 100 = 65000 ways to choose vehicle numbers.
Solution:
Out of 26 alphabets two distinct letters can be chosen in 26P2 ways.Coming to numbers part, there are 10 ways (any number from 0 to 9 can be chosen) to choose the first digit and similarly another 10 ways to choose the second digit.
Hence, there are totally 10 × 10 = 100 ways.
Combined with letters there are,
26P2 × 100 = 65000 ways to choose vehicle numbers.