Question

We are all familiar with alpha numeric keypad that was used for messaging in earlier days. Given sequence of numbers 2-9 (both inclusive), find out the number of distinct alphabets that can be formed.

Answer 1

Solution: out of the 8 digits, number of digits selected can be written as 8C3 = 56 ways, similarly, 2 out of 5 alphabets = 5C2= 10 ways and 3 digits and 2 alphabets can be arranged as 5! = 120 ways.

Therefore, overall combination of the alphanumeric codes = 56 x 10 x 120 = 67200.