Plz. should be super easy but i'm having troubles figuring it out for some reason.

5,600 x 10^3 = a) 560 b) 5,000,600 c) 5,600,000 d) 56,000

Which recursive formula can be used to determine the total amount of money earned in any year based on the amount earned in the previous year? f(n+1)=f(n)+5

Liz is shipping a package to her friend.the maximum weight of a medium flat-rate box is 20 pounds,including the box which weighs 6 ounces.write and solve an inequality to describe the possible weight ,w, of the contents that liz will ship to her friend if she must use a medium flat-rate box.