Some goods are sold at a discount of 20%. If the same goods are sold without discount, their price will change by :

1. 25% increase

2. 25% decrease

3. 20% increase

4. 20% decrease

The marked price of an article is ₹ 400. If tax on it increases from 10% to 15%, the amount of it will increase by:

1. ₹ 30

2. ₹ 40

3. ₹ 60

4. none of these