Number of 2 digit even numbers that can be formed from the digits 1, 2, 3, 4 and 5 when repetitions are not allowed is

Two digit even numbers are formed using 1, 2, 3, 4, 5.

Consider 2 places. Units place can be filled using 2, 4 in 2 ways.

First place can be filled using remaining 4 digits in 4 ways.

No of permutations=4×2=8