If 20% of a water bill is deducted, then Rs. 100 is still to be paid. How much was the original bill?

110 120 125 135

125

If 20% of water bill is deducted, then 80% is still to be paid. So, according to the question: 80% = Rs. 100  Original bill before deduction amounts to be = \(\frac{100 }{ 80}\) x 100 = Rs. 125