Question

At a video store you have two options for renting movies. You can pay $4 per movie or you can pay a one-time membership fee of $10 and then only pay $1.50 per movie. After how many movie rentals will the cost of the member ship be less than the cost of renting movies without the membership

Answer 1

Let's put this into equations which we can then solve. At $4 per movie, let's call the price 4x. At $10 membership and $1.50 per movie after that, let's set the price as 10+1.5x.

4x>10+1.5x
2.5x>10
x>4

It's after 4 movies that the membership become cheaper :)