### Home > INT3 > Chapter 7 > Lesson 7.1.3 > Problem 7-35

7-35.

Ryan has the chickenpox! He was told that the number of pockmarks on his body would grow exponentially until his body overcomes the illness. He counted

Ryan decides to use the points

and to write an equation for the exponential model. Use these points to write the equation of his function in the form .Substitute both points into the equation

and solve forand.According to your model, on what day did Ryan get his first chickenpox pockmark?

Solve for

, so October 22