The price of Maruti car rises by 30 percent while the sales of the car come down by 20%. What is the percentage change in the total revenue?

Explanation:-

Let initial price of Maruti Car be Rs. 100.
As price increases 30%, price of car will become, (100 +30% of 100) = Rs. 130.
Due to increase in price, sales is down by 20%. It means, it is going make 20% less revenue as expected after increment of price.
So, New revenue = (130 - 20% of 130) = Rs. 104.
The initial revenue was Rs. 100 which becomes Rs. 104 at the end. It means there is 4% increment in the total revenue.

Mind Calculation Method:

100==30%↑(price effect)==>130==20%↓(sales effects)==>104.
Hence, 4% rises.