"The boys and the girls"
Translation:Τα αγόρια και τα κορίτσια
More usual is κορίτσια. More formal, the opposite in sex and the same age of αγόρια. Not usual to call an relatively old woman both words. It's a bit rude and mocking for these ages, unless they are talking friends to each other. In case you have to call a girl formally the most usual is to call her δεσποινίς=miss, or κυρία=lady. For more intimate you can add a μου after. But be careful how you call a woman, as it usual in all languages i guess ;) :)