if you want to know what percent did Mr. Yoshikawa graded you can say:
60/75 = ?/100 so ? is:
60*100/75 = 80 % so he graded 80% of the papers and the rest of the papers was graded by his student so:
100% - 80% = 20% so his student graded 20% of the papers :)))
i hope this is helpful
have a nice day
