How to find value of f(1) on a graph

There were 816 people at a concert when a band started to play. after each song, only half the people stayed to hear the next song. how many people were left at the concert after x songs? write a function to represent this scenario.

Acredit card advertises an annual interest rate of 23%. what is the equivalent monthly interest rate?

How many kilometers are equal to 5 miles? use 1 mile ≈ 1.61 kilometers. !