Eating at McDonald's

You and a friend read in the newspaper that 7% of all Americans eat at McDonald's each day. Your friend says, "That's impossible!"

You know that there are approximately 300,000,000 Americans and about 13,000 McDonald's restaurants in the United States.

Do you think the 7% claim is true? Show the mathematical reasoning that supports your view.

A Weighty Problem

Here's the problem of the week:

In a group of five children, the average (mean) weight of each child was 72 pounds. When a sixth child joined the group, the average weight of each child became 73 pounds. What was the weight of the sixth child?

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1. Click on Post a Comment
2. Click Other under Choose an Identity
3. Type in your first name, school initial, and grade (Paul G3)
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5. Type your response in the box above.
6. Click on Publish Your Comment button

Five Digits of Fun

My thousands digit is the first that is perfect,
But if you’re not happy with that,
It’s also the product of the first two primes,
According to my precocious cat.

My units digit is the odd of those primes,
And if you look at it and my tens,
You’ll find a number divisible by three,
But not by the square of that, friends.

Now let’s look at my hundreds and thousands.
If you examine those two as they’re paired,
You’ll find they form a number divisible by
An even prime that’s been squared.

Now let’s look at my body in whole.
Five different digits you see,
In order (or not) you’ll find that they are
Divisible by nine, yes siree!

Problem:
1. Can you find the mystery number?
2. Is there more than one number? Explain how you found your numbers. Did you use any tricks?