5. Saad invested Rs. 12000 for 7 years. Return on investment is \( 12 \% \) for the first 3 years and 15 percent for the rest of the period. Calculate the total interest received by Saad under simple interest. \( \begin{array}{llll}\text { A) Rs. } 16320 & \text { B) Rs. } 16112 & \text { C) Rs. } 18520 & \text { D) Rs. } 11520\end{array} \) 6. A business requires a minimum expected rate of return of \( 12 \% \) on its investments. Present value at \( 10 \% \) is +2057 and Present value at \( 15 \% \) is \( (5920) \). Find IRR \( \begin{array}{llll}\text { A) } 12 \% & \text { B) } 11.3 \% & \text { C) } 11.9 \% & \text { D) } 14 \%\end{array} \)

Saad's total interest can be calculated by finding the interest earned for each period separately. For the first 3 years at 12%, the interest is \( \text{SI}_1 = \frac{12000 \times 12 \times 3}{100} = 4320 \). For the next 4 years at 15%, the interest is \( \text{SI}_2 = \frac{12000 \times 15 \times 4}{100} = 7200 \). Adding both gives a total interest of \( 4320 + 7200 = 11520 \). So, the answer is D) Rs. 11520. To determine the Internal Rate of Return (IRR), we can apply interpolation between the given present values at 10% and 15%. The present value at 10% is positive (+2057), and at 15%, it is negative (-5920). By estimating IRR using the formula \[( PV_{\text{10\%}} + |PV_{\text{15\%}}| ) \div ( |PV_{\text{15\%}}| + |PV_{\text{10\%}}| )\] and checking the ranges, we find the IRR falls around 12%. Thus, the answer is A) 12%.