The question presents a scenario where increased petrol prices lead to decreased consumption. Analyzing the provided data, we can observe a consistent inverse relationship. If the expenditure remains constant (Price x Consumption = Total Expenditure), a 25% increase in price from Rs. 60 to Rs. 75 resulted in a 20% decrease in consumption from 40 to 32 litres. This pattern suggests an elasticity where consumption decreases proportionally less than the price increase, implying a constant expenditure. Following this pattern, an increase in price from Rs. 75 to Rs. 80 (a 6.67% increase) would lead to a consumption decrease that maintains a similar expenditure level, pointing towards 30 litres as the most probable consumption.