COMEDK202510 May 2025Morning ShiftMathematicsPermutation and CombinationActual
Codes used for vehicle identification consists of two distinct English alphabets followed by two distinct digits from 1 to 9 . How many of them end with an even number.
Options
- A2600
- B20800
- C5200
- D10400
Correct answer
B. 20800
Step-by-step solution
The vehicle identification code consists of four positions: two distinct English alphabets followed by two distinct digits from 1 to 9. The number of ways to choose two distinct alphabets is ²⁶P₂ = 26 25 = 650 . The digits are chosen from the set 1, 2, 3, 4, 5, 6, 7, 8, 9 . There are 9 available digits. The code ends with an even number. The even digits in the set are 2, 4, 6, 8 , so there are 4 choices for the last digit. Since the digits must be distinct, the first digit can be any of the remaining 8 digits (9 to