Question: I was wondering how many $3$-Digits Even Numbers can be formed from $2,4,5$ ?
My Approach: If we take even number $2$ at extreme right _ _ $2$ then 2 permutations can formed from remaining numbers i.e ($4,5$), similarly if we take $4$ at extreme right _ _ $4$ then again 2 permutations will be formed. So,
Is my answer correct? because according to my teacher it should be 18.
Conclusion: Help will be highly appreciated and i want the clear method to solve questions of this kind in which any number digits either even or odd can be formed using any given numbers.
P.S.(Sorry for Bad English)