Question

How many even numbers greater then 300 can be formed with the digits 1,2,3,4,5 if repetitions of digits in a number is not allowed?

Answer 1

Number of 3 digit even numbers = $3\times 3$(when ending with 2) + $2\times 3$(when ending with 4) $=15$

Number of 4 digit even numbers = $2\times 3\times 4\times 2=48$

Number of 5 digit even numbers = $1\times 2\times 3\times 4\times 2=48$

Therefore, total number of numbers = $15+48+48=111$