Step 1: Marked Price of the Item.
The shopkeeper marks the item at 30% higher than the cost price. The marked price \( M \) is:
\[
M = 7825 \times \left( 1 + \frac{30}{100} \right) = 7825 \times 1.3 = 10172.5
\]
Step 2: Selling Price After Discount.
The shopkeeper sells the item by allowing a 20% discount on the marked price. The selling price \( S \) is:
\[
S = 10172.5 \times \left( 1 - \frac{20}{100} \right) = 10172.5 \times 0.8 = 8138
\]
Step 3: Profit and Profit Percentage.
The profit is:
\[
\text{Profit} = S - \text{Cost Price} = 8138 - 7825 = 313
\]
The profit percentage is:
\[
\text{Profit Percentage} = \frac{\text{Profit}}{\text{Cost Price}} \times 100 = \frac{313}{7825} \times 100 \approx 4%
\]
Final Answer: \[ \boxed{4%} \]
A weight of $500\,$N is held on a smooth plane inclined at $30^\circ$ to the horizontal by a force $P$ acting at $30^\circ$ to the inclined plane as shown. Then the value of force $P$ is:
A steel wire of $20$ mm diameter is bent into a circular shape of $10$ m radius. If modulus of elasticity of wire is $2\times10^{5}\ \text{N/mm}^2$, then the maximum bending stress induced in wire is: