Let the cost price (CP) of the product be \( x \) rupees. The selling price (SP) is fixed to ensure a 40% profit. Therefore, the SP is:
\[ SP = x + 0.4x = 1.4x \]
According to the problem, if the cost price were 40% less, it would be:
\[ 0.6x \]
And the selling price would be 5 rupees less, i.e.,
\[ 1.4x - 5 \]
In this scenario, the profit would be 50%, thus:
\[ 1.5 \times 0.6x = 1.4x - 5 \]
\[ 0.9x = 1.4x - 5 \]
Solving the equation:
\[ 1.4x - 0.9x = 5 \]
\[ 0.5x = 5 \]
\[ x = \frac{5}{0.5} = 10 \]
The original selling price is:
\[ SP = 1.4 \times 10 = 14 \]
Thus, the original selling price of the product is 14 rupees.
Let the original cost price be $C$, and the original selling price be $S$. We know that $S = C \times 1.40$. If the cost price is reduced by \(40\%\), the new cost price is $0.6C$, and the new selling price is $S - 5$. The new profit is 50
$S - 5 = 1.5 \times 0.6C \implies S - 5 = 0.9C$
Substitute $S = 1.4C$ into this equation:
\(1.4C - 5 = 0.9C\)
\(\implies 0.5C = 5\)
\(\implies C = 10\)
The original selling price is $S = 1.4 \times 10 = 14$.