There are 150 vehicles in a parking place. Each vehicle is either a bike or a car, and is either red or green. Sixty vehicles are red, and 100 vehicles are cars. If there are 20 green bikes, how many red cars are there?

Correct option is B

Given:
Total vehicles = 150
Red vehicles = 60
Green vehicles = 150 - 60 = 90
Cars = 100
Bikes = 150 - 100 = 50
Green bikes = 20

Solution:

Now, green vehicles = green bikes + green cars.
Thus, Green cars = Green vehicles - Green bikes
Green cars = 90 - 20 = 70

Now, Total cars = 100

Thus, Red cars = Total cars - Green cars
Red cars = 100 - 70
Red cars = 30

But wait, cross-verifying:

Red vehicles = 60

Red cars = ?

Red bikes = ?

If red cars = 30, then red bikes = 60 - 30 = 30.

Now bikes total = 50

Green bikes = 20

Red bikes = 30

Total bikes = 20 + 30 = 50 (matches)

Thus, everything is matching correctly!

Therefore, number of red cars = 30

Thus, correct answer is (b) 30

Final Answer: (b) 30