Understanding the Parking Place Vehicles

This problem is about classifying vehicles based on two attributes: type (bike or car) and color (red or green). We are given the total number of vehicles and some specific counts within these classifications. Our goal is to find the number of red cars.

Let's list the information we are given:

• Total vehicles in the parking place = 150
• Each vehicle is either a bike or a car.
• Each vehicle is either red or green.
• Total red vehicles = 60
• Total cars = 100
• Number of green bikes = 20

Vehicle Classification Categories

We can categorize the vehicles into four groups:

1. Red Cars
2. Red Bikes
3. Green Cars
4. Green Bikes

The sum of vehicles in these four groups must equal the total number of vehicles.

Calculating Missing Totals

We know the total number of vehicles and the total number of cars. We can find the total number of bikes:

• Total Bikes = Total Vehicles - Total Cars
• Total Bikes = $150 - 100 = 50$

We also know the total number of vehicles and the total number of red vehicles. We can find the total number of green vehicles:

• Total Green Vehicles = Total Vehicles - Total Red Vehicles
• Total Green Vehicles = $150 - 60 = 90$

Using a Table to Organize Data

It's helpful to visualize this information in a table:

Finding the Number of Bikes

We know the total number of bikes is 50 and that 20 of them are green bikes. The remaining bikes must be red bikes.

• Number of Red Bikes = Total Bikes - Number of Green Bikes
• Number of Red Bikes = $50 - 20 = 30$

Finding the Number of Cars

Now we can find the number of red cars using the total number of red vehicles and the number of red bikes we just found.

• Number of Red Cars = Total Red Vehicles - Number of Red Bikes
• Number of Red Cars = $60 - 30 = 30$

Alternatively, we could find the number of green cars first.

• Number of Green Cars = Total Green Vehicles - Number of Green Bikes
• Number of Green Cars = $90 - 20 = 70$

Then, find the number of red cars using the total number of cars and the number of green cars.

• Number of Red Cars = Total Cars - Number of Green Cars
• Number of Red Cars = $100 - 70 = 30$

Both methods give the same result.

Summary Table

Here is the completed table with all the counts:

Based on our calculations, there are 30 red cars.