- #1
22990atinesh
- 143
- 1
Homework Statement
A code consists of at-most two identical letters followed by at-most four identical digits. The code must have atleast one letter and one digit. How many distinct codes can be generated using letters A-Z and digits 1-9.
Homework Equations
The Attempt at a Solution
//One letter followed by one or more digits
##26 \times 10 + 26 \times 10 \times 10 + 26 \times 10 \times 10 \times 10 + 26 \times 10 \times 10 \times 10 \times 10 + ##
//two letters followed by one or more digits
##26 \times 26 \times 10 + 26 \times 26 \times 10 \times 10 + 26 \times 26 \times 10 \times 10 \times 10 + 26 \times 26 \times 10 \times 10 \times 10 \times 10##
But the ans is too big it doesn't matches with the result. What can be correct answer