By dilution formula
3*200+2*300=M*500
M=1200/500
M=22/5
AgNO3+NaCl ----> AgCl +NaNO3
no. of moles of AgNO3=12/5*500/1000 = 1.2mole
no. of moles of NaCl =10*200/1000 =2 mole here the given amount of AgNO3 is totally consumed ,so it is the limiting reagent.
Amount of NaCl left=0.8* 51.5
=46.8g