An automobile owner reduced his monthly petrol consumption when the prices went up. The price-consumption relationship is as follows:

Price (in `₹ per litre)	40	50	60	75
Monthly consumption (in litres)	60	48	40	32

If the price goes up to ₹80 per litre, his expected consumption (in litres) will be

The correct option is 30.

To find the expected petrol consumption when the price rises to ₹80 per litre, we need to analyze the relationship between the price of petrol and the monthly consumption from the given data.

Let the price per litre be represented by P and the monthly consumption in litres be represented by C.

Let us calculate the total monthly expenditure on petrol for each given price-consumption pair by multiplying the price (P) by the consumption (C):

For Price = ₹40:
Expenditure = 40 × 60 = ₹2400

For Price = ���50:
Expenditure = 50 × 48 = ₹2400

For Price = ₹60:
Expenditure = 60 × 40 = ₹2400

For Price = ₹75:
Expenditure = 75 × 32 = ₹2400

From the above calculations, we observe that the total monthly expenditure remains constant at ₹2400, regardless of the price. Mathematically, this constant relationship can be expressed as:

$$P\times C=2400$$

Now, we can use this relation to find the expected consumption (C) when the price (P) increases to ₹80 per litre:

$$80\times C=2400$$

Solving for C:

$$C=\frac{2400}{80}$$

$$C=30$$

Therefore, when the price goes up to ₹80 per litre, the expected monthly petrol consumption will be 30 litres.