Answer:144 ways
Step-by-step explanation:
Given
There are 7 different models cars
out of which three are blue and 4 are red
If the first middle and last car in Queue is blue car therefore the position of blue cars is fixed
But these 3 cars can be arranged in 3! ways
Remaining 4 cars can be arranged in remaining 4 spots in 4! ways
Therefore total no of ways are
[tex]=3!\times 4![/tex]
[tex]=6\times 24=144\ ways[/tex]