Final answer:
There were 4 people in each of the 6 cars used by a joint family of 30 members for their picnic, after accounting for the 6 additional people who traveled in a truck.
Step-by-step explanation:
To find out how many people were in each car, we need to divide the total number of people attending the picnic by the number of cars, given that each car has the same seating capacity and was fully occupied. After we calculate this, we need to account for the extra people who traveled in the truck.
First, we find the number of people who traveled in cars: 30 members - 6 members (in the truck) = 24 members traveling in cars. Now, we have to divide those 24 members by the 6 cars to find out how many people were in each car. So, 24 divided by 6 equals 4. Therefore, there were 4 people in each car.