why there was no explanation before the lesson ? I just don't get it http://cs303801.vk.me/u6602343/149374785/y_86ee00e9.jpg
To add to what va-diim wrote: in plural it doesn't matter much whether a noun is masculine or not. It's either 'masculine personal' (those = tamci) or it isn't. "koty", "kobiety", "drzewa", "dzieci" (cats/women/trees/children)... in plural they are in one category. "those" is translated as "tamte" for them.
There is no such thing as plural feminine, only virile and nonvirile. However, feminine nouns fall into the nonvirile category. I suggest you take a look at these two tables:
Also, the -ti ending just doesn't exist in Polish.
The rule is pretty straightforward: A determiner must be of the same gender, number and case as the noun which it is referring to. The noun here is kobiety (nonvirile, plural, nominative), therefore the demonstrative pronoun must also be: nonvirile, plural, nominative. You can easily find the correct form in a declension table: