I have 3 mysterious questions for you this week. Don’t worry, there will be a computer-related tip before we’re done here.

Mystery number 1: Why can’t I add simple numbers in my head?

This is just a simple addition problem. But you cannot use a calculator or a pencil and paper. This must be done completely in your head.

Try it:

Take 1000 and add 40 to it. Now add another 1000. Now add 30. Add another 1000. Now add 20. Now add another 1000. Now add 10.

What is the total?

I’ll put the answer at the end of this post. No cheating! Come up with the answer in your head and see if you got it right.

Mystery number 2: Where did the other dollar go?

This one has been one of my favorite word problems for many years. It seems so simple, but can be so confounding.

Here’s the story:

Three men are traveling and stop for the night at a hotel.

They decided they want to save some money and share a room. The clerk tells them that a room for the night is $30.

So each man pays $10, and they go up to the room.

A little while later, the clerk realizes that he made a mistake. The room was only supposed to be $25.

So he gives the bellhop $5, and tells him, “I overcharged the 3 men – go and give them this $5 back.”

The bellhop heads toward the room, but he’s not very honest. On the way to the room, he decides to keep $2 for himself. He goes to three men and only gives them back $3 (which of course is a refund of $1 each).

Now let’s think about this. We started out with the men paying $30 total, right?

So originally each man paid $10. Now each man got a dollar back, which means that each man has now paid $9.

$9 x 3 men = $27. The bellhop kept $2. That’s $29.

Where did the other dollar go?

Mystery number 3: Why do people continue to pay for a service that they no longer use?

This question is the one that’s computer/internet related.

A long time ago, back when the internet was still a new toy to a lot of people, America Online was a very popular Internet Service Provider. Most people still had dial-up service. And no matter where you went, there was a display of AOL computer discs – always free – that would install the AOL software on your computer. This would create an account for you to connect to the internet, and back then it was like $9.95 per month. It gradually grew to $12 and later $15 per month.

That monthly fee was what allowed the customer to actually connect to the internet.

Fast forward to today. Most people now use cable or some other type of high-speed internet connection. There are still some people (like those in very rural areas) who use AOL’s dialup internet service, but that number is steadily declining as high-speed access spreads.

But guess what – many of the people that no longer use AOL to connect to the internet still pay AOL for that monthly subscription.

It’s true. The average AOL “subscriber” currently pays $21.35 per month and AOL continues to increase the monthly fee by adding on additional “services” such as antivirus and premium tech support. But millions of those people don’t even use AOL’s service because they have switched to a high-speed internet connection.

In fact, in the most recent fiscal quarter, the division of AOL that includes dialup service took in $139 million. With a continually declining user base, the one thing keeping AOL alive right now are these millions of people that are paying for nothing.

For some of these people, I know the reason why because I have talked to them personally. They think that in order to keep their AOL email address they need to keep paying their monthly subscription. This is not true. AOL email is free (and in my opinion, even that is overpriced).

So here’s the computer tip for today: if you are still paying AOL just to keep your email account, stop! Cancel your AOL subscription. You won’t lose your email address. And when you do cancel, check your credit card statement to make sure they don’t just “forget” and keep charging you anyway – that’s the standard practice for AOL.

And the correct total for the first mystery question is 4100. Most people, myself included, come up with 5000. Get a calculator and check it.