What score is 60 percentile quant?

I believe that I have done my best to prepare for the quant portion of the GMAT so I will be taking the real exam soon. I scored a dismal 35% on quant on my last attempt and am striving to get at least 50th percentile. 60th percentile would be awesome! My target school is willing to work with my current 640 overall score but wants me to get at least a 50th percentile (not 50Q) on quant even if my verbal drops a little. About what score do I need to get there? 43Q? 45Q? Last time I got a 35Q and a 44V and the percentiles were 35% and 97%, respectively.

Thanks!

Jose