A car owner buys petrol at the rate of Rs 62.50, Rs 52.50 and Rs 57.50 per litre for three successive years. What is the average rate per litre of petrol, if he spends Rs 24150 each year?

Options

A. Rs 57.21
B. Rs 57.50
C. Rs 52.50
D. Rs 56.20

Answer

To find the average rate per litre of petrol over three years, we can follow these steps:

### Step 1: Calculate the total petrol purchased each year
The cost of petrol each year is given as Rs 24,150. We need to find out how many litres of petrol were purchased each year at the different rates.

1. **For Year 1 (Rate: Rs 62.50 per litre)**:
\[ \text{Litres} = \frac{\text{Total Cost}}{\text{Rate}} = \frac{24150}{62.50} = 386.4 \text{ litres} \]

2. **For Year 2 (Rate: Rs 52.50 per litre)**:
\[ \text{Litres} = \frac{24150}{52.50} = 460 \text{ litres} \]

3. **For Year 3 (Rate: Rs 57.50 per litre)**:
\[ \text{Litres} = \frac{24150}{57.50} = 420 \text{ litres} \]

### Step 2: Calculate the total petrol purchased over three years
Now, we add the total litres purchased over the three years:
\[ \text{Total Petrol} = 386.4 + 460 + 420 = 1266.4 \text{ litres} \]

### Step 3: Calculate the total amount spent over three years
The total amount spent over three years is:
\[ \text{Total Amount} = 24150 \times 3 = 72450 \text{ Rs} \]

### Step 4: Calculate the average rate per litre
Now, we can find the average rate per litre of petrol:
\[ \text{Average Rate} = \frac{\text{Total Amount}}{\text{Total Petrol}} = \frac{72450}{1266.4} \approx 57.21 \text{ Rs per litre} \]

### Final Answer
The average rate per litre of petrol is approximately **Rs 57.21**.

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