Translation:How many girls have a green shirt?
I said green jumper and it was marked wrong it should be pullover! They are the same thing!!
Does the color not match the gender with the noun? I used maglia verda (I did hear it as maglia verde, but it didn't sound correct to me)
Verde (and most nouns/adjectives ending with '-e' in the singular) is gender-invariant: "la maglia verde", "le maglie verdi", "il cappello verde", "i cappelli verdi", "il fiore verde", "i fiori verdi".
La maglia is the T-shirt and la camicia is the shirt, with a collar and buttons. You can use Google Images to get a better idea how it looks like.
In previous sentences the British English "jumper" was accepted as a translation of "maglia" but here it is marked wrong.