Can I get help with both I’m confused

3. find the radius of circle p.4. find y.

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

Nour and rana are shopping for a christmas tree. they are deciding between 2 22 different types of trees (real and fake) and 4 44 colors for the ornaments (white, silver, gold, and purple). they each created a display to represent the sample space of randomly picking a type of tree and a color for the ornaments. whose display correctly represents the sample space?