In this assignment, use our format for homework (title page with code name, etc, and headers on other pages). Also use a bold, underlined  title  for each problem.

Within each problem:

* Restate the problem as the first paragraph(s) of each problem.

* Provide your analysis of the problem as the second paragraph.  (You don’t need to use “my” steps.)

* Include/create an explanatory “drawing” created using Paint or Word's Drawing Toolbar.

(You don’t have to get the “right” answer!! Just try out your "analysis" skills.)

 

Remember: You need to create a picture or drawing of some sort for each problem.

 

THE FIRST PROBLEM was (or will be) covered in class. This is your chance to present your explanation. Be sure to include some sort of drawing. (I would have used a ‘time line’, for instance). 

A statement of the problem:

A remote Post Office in eastern Montana sends an employee to the “airport” each day to fetch the mail. The employee rides a motorcycle, and has done it often enough to be able to arrive at the airport just as the plane lands. One day the plane arrives early, and the manager of the airport decides to start the mail moving toward the Post Office. Fortunately, a former rider for the Pony Express dropped by to watch the plane land, and is persuaded to carry the mail once again (but without pay). So, off he goes with the mail, headed in the general direction of the Post Office. Half an hour after the plane landed, the rider meets the motorcyclist, and gives him the mail. The motorcyclist heads for the Post Office, and the horseman heads home. The motorcyclist arrives back at the Post Office 20 minutes earlier than his usual time (which causes great confusion). So, how early was the airplane?

 

 

THE SECOND PROBLEM is a party trick.

There are 8 glasses on the table, arranged in a row. You fill the first 4 glasses. Now you challenge someone to rearrange the glasses, so that they will alternate in a pattern of full, empty, full, empty, and so on. The person is allowed 4 moves to accomplish the feat, where a move consists of shifting two adjacent glasses. They will still be adjacent to each other after the “shift”. ("Adjacent" means their rims are less than one-half inch apart.)

 

 

THE THIRD PROBLEM is for sailors. (But you have to do it even if you’re not a sailor.)

When the U.S.S. Enterprise arrived at San Diego, it needed some work done on its hull. (Paint chipping, to those of you who were formerly in the Navy.) A rope ladder was hung over the side. It had rungs spaced one foot apart, and the ladder extended until the bottom-most rung just touched the surface of the water at low tide. The water in the bay rises about 12 inches every two hours. How many rungs were under water 7 hours later, when the tide peaked?

 

 

Back to CS 172 Page