Every year a herd of buffalo increase by 50%. Suppose that at year 0 there are 60 buffalo, and each year 20 buffalo leave the herd. a) How many buffalo are there at year 3? (Write the integer closest to your answer.) b) Back to year 0, if the park rangers control how many buffalo leave, then how many should they set free for the herd's population to be stable?

In a certain company 80 of the employees are men. What is the total number of employees if 5 out of every 8 employees are men?

One morning Dave an email message to Alvin that said the following: “You are one of my dearest friends. If you care about me, send a copy of this letter to two of your dearest friends tomorrow. If you do not break this chain, you will live long and prosper.” Alvin followed the directions: the next day he sent a copy of the message to two of his dearest friends. The following day, each of the recipients did the same. Count the day Dave sent the original message as the first day, and assume the chain is unbroken. A. How many copies of the message will be sent on the sixth day? B. Find the n-rule that will show how many copies of the message will sent on the n-th day.

A farmer knows that of every 50 eggs his chickens lay, only 45 will be marketable. If his chickens lay 1900 eggs in a week, how many of them will be marketable?