How many pull ups can you do?

[Zeus]

for gym we have to do 25 pull ups with 5 pound anckle weights on*for a test*

but nornally we just do 15 for warms ups,with 10 push ups and 20 sit ups

I've never actually tryed low weight high rep pull ups. I've always stuck to low rep high weight for strength and not just conditioning and like rippness :P