50. Some parking meters in Milan, Italy, accept coins in the denominations of 20c/, 50c/, and C2. As an incentive program, the city administrators offer a big reward (a brand new Ferrari Testarossa) to any meter maid who brings back exactly 1,000 coins worth exactly C1,000 from the daily rounds. What are the odds of this reward being claimed anytime soon

Okay, let's set this up as an equation, shall we?

Tonya printed 30 copies, each using 16 sheets of paper, so we're going to need to do some multiplying to figure out just how much paper she needs (30 x 16). 

But wait a sec! Tonya, being the lucky duck she is, is extra prepared and has more paper than she needs. She has 20 sheets leftover, so we'll just add this on to our product of 30 and 16, which gives us the equation: 30 x 16 + 20.

Now let's solve:
30 x 16 = 480
480 + 20 = 500.

Tonya then started out with 500 pages.

Hope this helps!