What kind of brush are we talking about? Toothbrush? Paintbrush? Toilet brush?
We don't know it without a context, either in English or in Portuguese.
Native speakers, what is the translation? I'm a little suspicious of what Duolingo says.
Yes, it is wrong. Você precisa da escova? = do you need THE brush? / você precisa escovar? = do you need to brush?
Dumpsey, If it were presica it would be pronounced prehseekah, c makes the s sound when followed by i and k if follow by a so it has to be precisa to be pronounced prehseesah. Hope that helps you remember.