3.9 meters long 6% shorter

3.9 (100-6) / 100

3.9 (94) / 100

366.6/100

3.666 meters

So what we want to know is how long is the car that is 6% shorter then the other car. We can look at it this way: the shorter car is 94% the lenght of the longer car. Lets call the length of the shorter car x, then we have the equation: 94% * 3.9m=x. Or, (94/100) * 3.9=x. Now we solve for x and get: x = 3.666m. So the shorter car is 3.666 m long.