There are 144 people in the audience. The ratio of adults to children is 5 to 3. How many adults are

There are 144 people in the audience. The ratio of adults to children is 5 to 3. How many adults are there?

Let x be the number of people, we have:
5x + 3x = 144

Typing this problem in our search engine, we get x = 18.

Which means we have 5(18) = 90 adults