1. **State the problem:** You buy a TV for 800 shs paying in 18 equal monthly installments at an interest rate of 1.5% per month on the unpaid balance. We want to find: - (a) The monthly payment amount. - (b) The total interest paid. 2. **Identify variables:** - Principal $P = 800$ - Monthly interest rate $i = 1.5\% = 0.015$ - Number of payments $n = 18$ 3. **Use the annuity formula for equal payments:** $$ A = P \times \frac{i(1+i)^n}{(1+i)^n - 1} $$ where $A$ is the monthly payment. 4. **Calculate $ (1 + i)^n $:** $$ (1 + 0.015)^{18} = 1.015^{18} \approx 1.3048 $$ 5. **Calculate the numerator:** $$ 0.015 \times 1.3048 = 0.019572 $$ 6. **Calculate the denominator:** $$ 1.3048 - 1 = 0.3048 $$ 7. **Calculate monthly payment $A$:** $$ A = 800 \times \frac{0.019572}{0.3048} = 800 \times 0.06423 = 51.38 $$ So monthly payment is approximately 51.38 shs. 8. **Calculate total amount paid:** $$ \text{Total paid} = 51.38 \times 18 = 924.84 $$ 9. **Calculate total interest:** $$ \text{Interest paid} = \text{Total paid} - P = 924.84 - 800 = 124.84 $$ **Final answers:** - a) The monthly payment is approximately **51.38** shs. - b) The total interest paid is approximately **124.84** shs.