Question 14 Marks
Divide Rs. 20304 into two parts such that if one part is invested in 9% Rs. 50 shares at 8% premium and the other part is invested in 8% Rs. 25 shares at 8% discount, then the annual incomes from both the investment are equal
Answer
View full question & answer→Total amount = Rs 20304
Let amount invested in $9 \%$ Rs 50 at $8 \%$
premium $=x$
Then amount invested in $8 \%$ Rs 25 at $8 \%$
Discount $=20304- x$
Income from both investments are equal Now income from first type of shares
$
=\frac{x \times 9}{100+8}=\frac{9 x}{108}=\frac{x}{12}
$
Income from second type of shares
$
\begin{aligned}
& =\frac{(20304-x) \times 8}{100-8} \\
& =\frac{(20304-x) \times 8}{92} \\
& =\frac{2(20304-x)}{23}
\end{aligned}
$
$\because$ In both cases, annual income is same
$
\begin{aligned}
& \therefore \frac{x}{12}=\frac{2(20304-x)}{23} \\
& \Rightarrow 23 x =24(20304- x ) \quad \ldots(\text {By cross multiplication) } \\
& \Rightarrow 23 x =24 \times 20304-24 x \\
& \Rightarrow 23 x +24 x =24 \times 20304 \\
& \Rightarrow 47 x =24 \times 20304 \\
& \therefore x =\frac{24 \times 20304}{47}=10368
\end{aligned}
$
$\therefore$ Amount invested in first kind of shares
$
=\text { ₹ }10368
$
and in second kind of shares
$
\begin{aligned}
& =\text { ₹ } 20304 \text { - \text { ₹ }10368 } \\
& =\text { ₹ } 9936 .
\end{aligned}
$
Let amount invested in $9 \%$ Rs 50 at $8 \%$
premium $=x$
Then amount invested in $8 \%$ Rs 25 at $8 \%$
Discount $=20304- x$
Income from both investments are equal Now income from first type of shares
$
=\frac{x \times 9}{100+8}=\frac{9 x}{108}=\frac{x}{12}
$
Income from second type of shares
$
\begin{aligned}
& =\frac{(20304-x) \times 8}{100-8} \\
& =\frac{(20304-x) \times 8}{92} \\
& =\frac{2(20304-x)}{23}
\end{aligned}
$
$\because$ In both cases, annual income is same
$
\begin{aligned}
& \therefore \frac{x}{12}=\frac{2(20304-x)}{23} \\
& \Rightarrow 23 x =24(20304- x ) \quad \ldots(\text {By cross multiplication) } \\
& \Rightarrow 23 x =24 \times 20304-24 x \\
& \Rightarrow 23 x +24 x =24 \times 20304 \\
& \Rightarrow 47 x =24 \times 20304 \\
& \therefore x =\frac{24 \times 20304}{47}=10368
\end{aligned}
$
$\therefore$ Amount invested in first kind of shares
$
=\text { ₹ }10368
$
and in second kind of shares
$
\begin{aligned}
& =\text { ₹ } 20304 \text { - \text { ₹ }10368 } \\
& =\text { ₹ } 9936 .
\end{aligned}
$