Answer to Question #269607 in Statistics and Probability for samuela

Question

Suppose repetitions are not permitted. How many three digit even numbers greater than 500 can be formed from the six digits 2, 3,5,6,7, 9. 

Answer 1

The first digit will be 5 or 6 or 7 or 9

Total = 4 ways

The second digit will be any remaining number.

Total = 5 ways

The third digit will be only even numbers 2 and 6

Total = 2 ways

By the law of Multiplication the required number of digits $= 4 \times 5 \times 2 = 40$