How many 3 digit even numbers can be formed from the digits (0-9) if repetition of digits are allowed?
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 450
Fill the three places one by one and multiply the number of choices for each (repetition is allowed, so each choice is independent).
Hundreds place: any digit except 0 (a number cannot begin with 0): 9 choices
Tens place: any of the 10 digits: 10 choices
Units place: an even digit (0, 2, 4, 6, 8), so that the number is even: 5 choices
Total \(=9\times10\times5=450\)