If you start with clean slate - no EVs - then yes, you can get 100 EVs in five stats.

EVs done EZ:

'Roids: Protein, Carbos, Zinc, etc. All these pills give your Pokemon 10 EVs per pill up to 100 EVs in that given stat, providing you haven't capped your 510 EVs. If you've already done about 400+ EVs for your Pokemon (say 252 Atk, 208 Speed) and you want to put the rest in another stat, if you max out EVs with pills (say HP Ups) it will just fill out what you're missing and then you won't be able to use anymore. It's pretty simple, there are two basic limits, as I've said: 100 capped EVs (total) in any given stat for pills, 510 max EVs.

Friendship Berries: These are pretty simple, but have a unique twist to them. They remove 10 EVs from the given stat unless you have more than 100 EVs in that given stat. If this is the case, the EVs in that given stat will be lowered to 100 on the first use, and each subsequent use will lower the EVs by 10. Yes, this works even if you've put 255 EVs in a Pokemon's stat, the first berry will remove 155 EVs.


Hope this helps a bit for those who are confused.