If we have 3 critical numbers how many intervals will we have ?

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.

What is the y intercept of f(x)=(1/2)^x?

Two variables, x and y, vary inversely, and x=12 when y=4. what is the value of y when x=3?