Two of January's Math Puzzlers
have same characters

Mr. Math Puzzler decided he likes the dwarfs Dobbit and Mobbit. So, he used those characters in two of the six Math Puzzlers for January.

So, you'll be able to use some of the math you used to solve Question 5 when trying to answer Question 6.

That sounds like a pretty good deal. However, what if you don't get the correct answer for Question 5? It might mean you'll be on the wrong track for Question 6 also. So, whatever you do, be careful with both questions.

Young Saint Louis.com likes it when kids that enter the Math Puzzler competition get the right answers. We get to list the winners the next month. We also get a chance to give out $10 Borders gift certificates as an extra bonus.

In the December contest, there were nine kids who answered all six of the questions correctly. (To read about the December winners and answers, click here.)

Before you try the December questions, you might check the past questions and answers. That way, you'll learn how Mr. Math Puzzler thinks.

YSL.com started the Math Puzzlers 1 and 1/2 years ago. To check questions, go to the Past Stories tab at the top of the home page. Click on any month since September, 2001, and you can check both questions and answers. (The answers to one month's questions are available in the next month's edition.)

Now, you should be ready for the January contest.

If you get all Puzzlers correct, YSL.com will print your name and those of all other winners in the January, 2003, edition. Remember, all winning entries also get a chance to win a $10 Borders gift certificate. We pick up to three winners for the certificates.

A reminder: These Math Puzzlers can be quite challenging, especially for younger kids. Remember, we don't mind if you get help from a parent or older brother or sister. In fact, you might want to make this a family activity.

Here's how to enter:

1. Print out the following entry form.
2. Fill out your name, address and telephone number.
3. Give your answers to the six Math Puzzlers.
4. Put your completed entry into a stamped envelope.
5. Mail your entry to:
   
   Math Puzzler Contest
   Young Saint Louis.com
   231 So. Bemiston Ave., Suite 800
   Clayton, MO 63105
   (This is a new address)
   
   
6. All entries must be postmarked by the 15th of the month to be eligible for a book prize.

-------------Clip here to make entry-------------

Entry for January, 2003, Math Puzzler Contest:

Name: ____________________________ Age: ________

Address: __________________ School: ______________

City:___________________, State:______ ZIP_________

Contact phone no.(____)____________________

The Math Puzzlers
(January, 2003)

1. While you are raiding your refrigerator, you look behind the stove and discover a slice of bread that you misplaced several weeks ago. Needless to say, it is covered with mold. Since the mold started growing, the area it has covered has doubled each day. By the end of the eighth day, the entire surface of the bread was covered. When was the bread half-covered with mold?

Answer:_______________

 

2. Suppose you have a three-wheeled car with one spare tire. You rotate tires regularly enough that each tire gets equal usage over a 50,000-mile span. How many miles will there be on each tire at the end of that distance?

Answer:_____________

 

3. Place the numbers 1,2,3,4,5 and 6 in the circles below so that the sums of the three numbers on each side are equal?

Answer:_____________

 

4. Once a week, a wagon driver leaves his hut and drives his oxen to the river dock to pick up supplies for his town. At 4:05 p.m., one-fifth of the way to the dock, he passes the smithy. At 4:15 p.m., one-third of the way, he passes the miller. At what time does he leave his home?

Answer:______________

 

5. The dwarfs Dobbit and Mobbit are building a bridge over a narrow stream. Dobbit can do the job alone in 30 hours; Mobbit can do the job alone in 45 hours. How long would it take them if they work together?

Answer:______________

 

6. Suppose Dobbit (from problem No. 5 above) worked on the project alone for 5 hours. How long would it take Dobbit and Mobbit to complete the rest of the job working together?

Answer:______________