You leave your house with 30 dollars. You spend an unknown amount of money on food and then spend 10 dollars on a movie. If you count that you have 5 dollars left, how much money did you spend on food?

15 dollars spend on food.

Step-by-step explanation:

As given

You leave your house with 30 dollars.

You spend an unknown amount of money on food and then spend 10 dollars on a movie.

Let us assume that the unknow amount of money spend on the food be x.

As given

If you count that you have 5 dollars left.

Than the equation becomes

30 - 10 - x = 5

20 - x = 5

20 - 5 = x

x = 15 dollars

Therefore the 15 dollars spend on food.