Question: About ilan and how to say how many people are in a pla

You would use the word "Mayroon", "Meron" or "May", which roughly means " There is/are".Mayroong sampung babae sa (insert place).Cheers!

Yes, you say "[number] ang babae." For example, if someone asked "Ilan ang babae?", you can say "Sampu ang babae", which literally translates to "The women are ten", but would be understood as "There are ten women". It would not be misinterpreted as their age because Tagalog and English can differ in sentence structure.
However, note that "mga" cannot be placed after "ang" in sentences like these, so "Sampu ang mga babae" would sound odd to Tagalog speakers.

“Ilán” is “how many”. “Ilán ang babae sa (location)?” means “how many women are in (location)?” and nothing else. (“Babae” means either “girl” or “woman”).If you’re asking about a woman’s age, it has to be “Ilang taón ang babae? (how old is the girl/woman?)”. “Ilang taon” is “ilan na taon”, which literally translates to “how many, that is, years”. The question “Ilan ang babae sa (location)?” may be answered in any of the following ways: (Assuming there are 10 of them)Sampû. = Ten.
Sampu ang (mga) babae. = Ten are women.
Sampu sila. = They are ten.
Sampu ang (mga) babae sa (location). = Ten are women in (location).
Sampu sila sa (location) = They are ten in (location).
Sampu silang (sila na) mga babae. = They are ten (that are) women. - “Sila na mga” = they that/who are
Sampu silang (sila na) mga babae sa (location). = They are ten (that are) women in (location).(I tried to give the English translations as close as possible to the Tagalog sentence structure for the benefit of the Beginners, but I leave the proper English translations to you.) Notes: 1. The above examples may be used whether they are all women in the location or there are boys/men with them.
2. In the last 2 examples you may also omit the “mga”, but I think some of us would prefer to have it there.
3. “Sampu” is normally pronounced with the stressed glottal stop at the end, but in the sentences where “sila/silang” follows it, in our normal speed of talking, only the stress is applied and the glottal stop disappears. It may sound to you as if we said them as a single word “sampúsiláng”These 2 sentences may be used only if the group is not exclusively female:Sampu sa kanila ay mga babae. = Ten of them are women.
Sampu sa kanila na/kanilang nasa (location) ay mga babae. = Ten of them (that are) in (location) are women.
Sampu ang mga babae sa kanila na/kanilang nasa (location). = Ten are women among them who are in (location).
___The sentences above are enough for you to learn and get by as a non-native speaker. What follows are for those who are interested in grammar structure or would like to go a bit beyond the basics.Beginning with the second sentence in the possible responses given above, their “ay” forms (active voice structures, which indicate that the part to the left of “ay” is or contains the subject of the sentence) are:Ang mga babae ay sampu.
Sila ay sampu.
Ang mga babae sa (location) ay sampu.
Sila ay sampu sa (location).
Silang mga babae ay sampu.
Silang mga babae sa (location) ay sampu.Ang mga babae sa kanila ay sampu.
Ang mga babae ay sampu sa kanila na/kanilang nasa (location).
Ang mga babae sa kanila na/kanilang nasa (location) ay sampu.It is more likely for us to have the “mga” there when the sentence is in the “ay” form. As @adrian313 suggested, you may also respond with: May/Mayroong (mayroon na)/Merong (meron na) sampung (sampu na) (mga) babae sa (location). = There are 10 women in (location). - We would most likely use “may” instead of “mayroong/merong”.Using the "ay" form: Sa (location) AY may/mayroong/merong sampung (mga) babae. - Note that the location becomes the subject of the sentence and could translate to “The (location) has 10 women in it”. - In case you’d like to use “mga” in the sentences, just be careful as to where you’d place it. It has to be between the adjective (sampu) and the noun (babae) – sampung MGA babae. If it is placed before the noun (MGA sampung babae) the meaning would change to “There are ABOUT 10 women in the (location)”.

@qwertytyper There is no problem with having "mga" there and it wouldn't sound odd at all to us. It's just that since "sampu" was mentioned ahead, then the plurality is already obvious that some of us may opt to remove the "mga". However, if we'd state that sentence in its "ay" form, it becomes "Ang babae ay sampu". It will still be understood based on context, but the singular subject and its plural complement are not in agreement. We would then be more inclined to say that as "Ang mga babae ay sampu" to make it grammatically correct. So, "Sampu ang mga babae" is just the rearrangement of the grammatically correct sentence.

@ramblecat ilan ang tao sa lugar na yun? Ilan ang babae ilan ang lalaki? There are words and sentences that cannot be translated literally and word by word!
The best translation i can give is "what is the density ratio of male and female in that place? Sa tanong na yan maiitindihan agad na hinihingi mo ang bilang ng babae at bilang ng lalaki sa lugar na yon! Hope i satisfy you.