To find the number of selections that include cars of at least 2 different colours, we consider all possible combinations of selecting 3 cars from the 12 available, and then subtract the combinations where all selected cars are of the same colour.

First, calculate the total number of ways to select 3 cars from 12:

\(\binom{12}{3} = 220\)

Next, calculate the number of ways to select 3 cars of the same colour:

• All red: \(\binom{5}{3} = 10\)
• All white: \(\binom{4}{3} = 4\)
• All black: \(\binom{3}{3} = 1\)

Total ways to select 3 cars of the same colour:

\(10 + 4 + 1 = 15\)

Therefore, the number of ways to select 3 cars with at least 2 different colours is:

\(220 - 15 = 205\)