A woman borrowed Rs 10000 from a bank at a 10% annual interest rate. What is the amount she must pay after five and a half years?

Principal amount P = Rs. 10000

Time period T = 5$\frac{1}{2}$ years = $\frac{11}{2}$ years

Rate of interest R = 10% p.a.

Formula:

Simple interest = $\frac{\mathrm{P} \times \mathrm{T} \times \mathrm{R}}{100}$

Calculation:

SI = $\frac{10000 \times {\displaystyle \raisebox{1ex}{$11$}\!\left/ \!\raisebox{-1ex}{$2 \times 10$}\right.}}{100}$

SI = Rs. 5500

Amount = Principal amount + Interest

A = Rs. 10000 + 5500

A = Rs. 15500

Hence, the correct answer is Rs. 15500.