To dispose of the old stocks, a person sold a tea-set for ₹ 3,420, which was 43% below the cost price. In order to make a profit of 10% the seller should have sold the set for ₹ ....... more.

Suppose, the cost price of the tea-set is x rupees.

Now, 43% below the cost price means $$\left(x-0.43x\right)$$ rupees, which is given as Rs. 3420.

So, the equation will be $$x-0.43x=3420$$

$$0.57x=3420$$

$$x=\frac{3420}{0.57}=6000$$

Thus, the cost price of the set is Rs. 6000.

If the percentage of profit is 10% , then the amount of profit=$$\left(6000\times0.10\right)=600rs$$  rupees, that means the selling price will be: (6000+600)rupees = 6600 rupees.

So, in order to make a profit of 10% , the seller should have sold the set for$$\left(6000-3420\right)=3180rs$$ rupees more.

option A is correct Answer