Set up bills Earnings function E(n) where n is the number of newspapers he sells:

E(n) =. Cost per newspaper * number of newspapers sold + base salary

E(n) = 0.2n + 25

We're asked to find n when E(n) = 47, so we set E(n) = 47 and solve for n:

0.2n + 25 = 47

Using our equation solver, we get:

n =

**110**