Total Error Rate
          .10            .05             .01
c = 2  0.0513167     0.0253206       0.00501256 
    3  0.0345106     0.0169524       0.00334451
    4  0.0259963     0.0127415       0.00250943
    5  0.0208516     0.0102062       0.00200805


tot := 1 - (1 - alph)^c
Table[Solve[tot == .05, alph], {c, 2, 5 ,1}]
{{{alph -> 0.0253206}
 {{alph -> 0.0169524},
 {{alph -> 0.0127415},
 {{alph -> 0.0102062},

Table[Solve[tot == .10, alph], {c, 2, 5 ,1}]
{{{alph -> 0.0513167},
 {{alph -> 0.0345106},
 {{alph -> 0.0259963},
 {{alph -> 0.0208516},

Table[Solve[tot == .01, alph], {c, 2, 5 ,1}]
{{{alph -> 0.00501256}, 
 {{alph -> 0.00334451}, 
 {{alph -> 0.00250943}, 
 {{alph -> 0.00200805},