Thanks for providing this; here is what I get from Google:
For the past seven days, Strahinja has been buying the same number of bags with pictures for the album every day. There are 6 pictures in each bag. Among these thumbnails were 10% duplicates. How many bags of Strahinja could he buy in the previous 7 days?
I suspect there is at least one error there, as Strahinja is not in bags.
Here is your original translation:
Peter have been buying each day same number of bags of stickers. In each bag there is 6 stickers. Whats the minimum number of stickers that Peter can buy if there will be 10% of duplicates?
Their grammar is a little better, and some different terms are used; but the important difference is that the
question is not the same. You said it was about how many
stickers he must buy; the original is about how many
bags to buy over
7 days. You implied that the (future)
goal is to have 10% duplicates; the original makes that an
observation (of the past). Finally, they don't use any word like "
minimum".
But now we can at least try to look at the math!
Unfortunately, it is still not at all clear what the problem is asking.
My understanding is that each bag contains 6 stickers (also called pictures or thumbnails), each different; and each day he buys some fixed number n of bags. It is observed that 10% of the stickers are duplicates, which I take to mean that out of x stickers, there are only 0.9x distinct stickers. But is that an observation for one day, or an average (expected value?), or the total of the seven days? Further, as stated, I take it to be a probability problem, in which case there would not be a definite answer. You called it beginning algebra, so we presumably have to interpret it "deterministically" -- that is, in a way that has a definite answer.
The only way I see to do so is to suppose that the 10% must be exact, so that the total number of stickers for the week must be a multiple of 10. That would make the problem easy (once you get past the barrier of interpretation).
In any case, I certainly don't like the problem.
(Incidentally, I've seen a number of problems in Serbian recently; Google on my computer doesn't do image translation, to my knowledge, and another site I've used doesn't happen to handle Serbian. But in one case it mattered enough to me that I used Google Translate on my phone, which I usually don't use for math stuff. I haven't tried that in this case.)