Q.A person's portfolio consists of 200 shares of face value ₹10 (dividend rate 12%, market value ₹15) and 100 shares of face value ₹100 (dividend rate 5%, market value ₹90). Find the total investment, the total annual dividend income, and the overall yield of the portfolio.

Total investment and total income are each found by adding the two holdings' own figures; overall yield is total income divided by total investment.

Total investment

Holding 1: $200\times15=₹3{,}000$. Holding 2: $100\times90=₹9{,}000$.

Total annual dividend income

Holding 1: dividend per share $=\dfrac{12}{100}\times10=₹1.20$; income $=200\times1.20=₹240$.

Holding 2: dividend per share $=\dfrac{5}{100}\times100=₹5$; income $=100\times5=₹500$.

Overall yield

$\text{Yield \%} = \frac{\text{Total income}}{\text{Total investment}}\times100 = \frac{740}{12{,}000}\times100 = 6.1\overline{6}\% \approx 6.17\%$ …

Computing the overall yield as a simple (unweighted) average of the two holdings' individual yields (e.g. $(8\%+5.56\%)/2=6.78\%$) instead of total income ÷ total investment — this is wrong whe …