Given:
White Car
Red Car
Black Car
Blue Car
Each color car is a factor of 36 ⇒ 2 * 2 * 3 * 3
There are twice as many white cars as red cars.
Assume Red cars is X ; then White cars is 2X.
The number of blue cars is twice that of black cars.
Assume Black cars is Y ; then Blue cars is 2Y.
The number of black cars is the product of two different prime numbers:
2 and 3 are prime numbers; they are also factors of 36. So, black cars is 2 times 3 is 6.
If Black car is 6, then blue cars is 12 (2 * 6).
Red cars is a square number that is not a multiple of 2. 2 and 3 are factors of 36. Square of 3 is 9. It is not a multiple of 2.
If red cars is 9, then white cars is 18 (2*9).
Total number of cars is 45.
White = 18
Red = 9
Black = 6
Blue = 12