Answer:
7 people are going in the minivan.
Explanation:
Since Chris AND the other 18 people are going, add 1 to 18 (19).
There are 3 cars, which have 4 each. We can use multiplication to determine that there are a total of 3 x 4 people in the cars, which is equivalent to 12.
Since the remaining party people are going in the minivan, we will subtract 12 from 19 to get 7.
Therefore, 7 people are going in the minivan.
Hope this helps!