How many cars are needed?

Question

There are 31 people going, and 4 including the driver could fit in each car. He announced to the group leader that 7 cars would be needed. That is not correct.  What is the mistake and how many cars are truly needed?

Answer 1

Let x = number of cars needed

4x=31

x=7 3/4

So, 7 cars wouldn't be enough; you need 8 cars.