Suppose that a Woodchuck logging machine can "chuck" (i.e., throw or hurl)

13 tons of wood an hour when freshly serviced, but that its performance decreases by 5 percent an hour until the next servicing. After a Woodchuck has been run for 12 hours since its previous servicing, how much wood can a Woodchuck chuck?

a. 7.02 tons per hour

b. 10.41 tons per hour

c. 13.00 tons per hour

d. 21.39 tons per hour