Three different cars are available to take 4 men and 1 woman on a particular journey. In how many different ways can the five people be allocated to the cars so that the woman is alone?

There does not seem to be enough details but you i would say these are a few:

Car1-Woman, Car2-one man, Car3 - 3 men

Car1 - 2 men, Car2 - 2 men, car3 - woman

Car1 - none, Car2 - 4 men, car3 - woman

You will have 3 in total

1. 2 men, 2 men, woman

2. 3 men, 1 man, woman

3. 4 men, woman

So 3