The selling price of an article is ₹ 1,000 and the tax on it is 10%. The increase of its tax if it increases to 15% is :

1. ₹ 500

2. ₹ 250

3. ₹ 50

4. ₹ 1,500

Selling price of an article = ₹ 1,000

and, Tax = 10% of ₹ 1,000

= $\dfrac{10}{100} \times ₹ 1,000$

= $\dfrac{1}{10} \times ₹ 1,000$

= $₹ \dfrac{1,000}{10}$

= $₹ 100$

Total amount to be paid = ₹ 1,000 + ₹ 100

= ₹ 1,100

When the selling price of the article = ₹ 1,000

and, Tax = 15% of ₹ 1,000

= $\dfrac{15}{100} \times ₹ 1,000$

= $\dfrac{3}{20} \times ₹ 1,000$

= $₹ \dfrac{3,000}{20}$

= $₹ 150$

Total amount to be paid = ₹ 1,000 + ₹ 150

= ₹ 1,150

The increase in tax = ₹ 1,150 - ₹ 1,100

= ₹ 50

Hence, option 3 is the correct option.