7 1/2% tax??
46.32 x 0.075 = 3.47
46.32 + 3.47 = 49.79
49.79 x 0.20 = 9.96
49.79+9.96 = 59.75
total bill = $59.75
NOTE: The question does not state if the tip is only on the bill or with tax included. Since the tax rate was given, I included the tax. Also, note, where I am from tips are paid based on the total bill including the tax.