Help me with this math homework, and also other lessons that I will publish please

Our goal is to collect email addresses from 60% of customers who purchase a product." so that means if i talk to 95 customers, i need to persuade to provide an email address?

Consider a cube that has sides of length l. now consider putting the largest sphere you can inside this cube without any point on the sphere lying outside of the cube. the volume ratio -volume of the sphere/ volume of the cube is 1. 5.2 × 10−1 2. 3.8 × 10−1 3. 1.9 4. 2.5 × 10−1 5. 3.8

How to find the exponential function y=ca^x, with points (1,2) and (2,1)