rank userid     158  159   sum
     1  zhuwenbi  35.0 50.0  85.0
     2  zhuyi     25.0 50.0  75.0
     3  zhangxin  31.5 40.0  71.5
     4  isc07211  40.0 30.0  70.0
     4  phanthix  35.0 35.0  70.0
     4  zhoujing  35.0 35.0  70.0
     7  akashkum  25.0 35.0  60.0
     8  chenting  28.0 25.0  53.0
     9  wangying  24.5 25.0  49.5
    10  lohyeong  28.0 20.0  48.0
    11  trianaku  21.0 25.0  46.0
    12  kohchung  15.0 20.0  35.0
    12  trantuan   0.0 35.0  35.0
    14  jonathan  15.0 17.5  32.5
    15  johansya   0.0  0.0   0.0
    15  ouyongji   0.0  0.0   0.0