To solve this, let's break down the problem step by step.

Step 1: Determine the number of cars and vans

The problem states the ratio of cars to vans is 3:7.

We know the total number of vehicles (cars + vans) is 160. Let’s represent the number of cars and vans as follows:

• Let the number of cars be $3x$
• Let the number of vans be $7x$

Since the total number of vehicles is 160: $3x + 7x = 160$ $10x = 160$ $x = 16$

Now, substitute $x = 16$ to find the actual numbers:

• Number of cars = $3x = 3 \times 16 = 48$
• Number of vans = $7x = 7 \times 16 = 112$

Step 2: Determine the number of cars using electricity, diesel, and petrol

• $\frac{1}{8}$ of the cars use electricity, so: $\text{Cars using electricity} = \frac{1}{8} \times 48 = 6$

• 25% of the cars use diesel: $\text{Cars using diesel} = 0.25 \times 48 = 12$

Step 3: Determine the number of cars using petrol

The rest of the cars use petrol. To find this, subtract the number of cars using electricity and diesel from the total number of cars: $\text{Cars using petrol} = 48 - 6 - 12 = 30$

Final Answer:

• Cars using electricity = 6
• Cars using diesel = 12
• Cars using petrol = 30

Would you like further details or clarification on any of the steps?

Here are some related questions for further practice:

1. How would the answer change if the ratio of cars to vans was different?
2. What would happen if the percentage of cars using diesel changed to 40%?
3. How do you calculate the number of vans using electricity, diesel, or petrol if the data were provided?
4. How can you apply the same method to solve similar ratio problems in other contexts?
5. Can you interpret a different scenario where vehicles use various types of fuel, such as hybrid, electric, and petrol?

Tip: When solving ratio problems, always check the total sum after solving the ratio to ensure consistency with the given total!