Three Cuts to Turn a Round Cake Into Eight Equal Slices

How can you cut a round cake three times to make eight equal slices?

Cut #1 – Down the center of the cake (vertically) leaving two equal halves.
Cut #2 – Across the center of the cake (horizontally) leaving four equal slices.
Cut #3 – Through the middle edge of the cake slicing all four of the pieces in equal halves, leaving eight equal slices (four equal tops and four equal bottoms).

Posted in Brain Teasers

Anyone Can Take It

Anyone can take it as long as it’s on someone.

Pity.

By Sef Daystrom

Posted in Riddles

False Positive HIV Test

Imagine an HIV test that is 95% accurate (false positive rate of 5%) and around 2% of the tested population is infected with HIV. What is the probability that you actually have HIV when your test comes back positive?

29%

To read more about this, see the False Positive Paradox page on Wikipedia.

Posted in Brain Teasers

I Know of Word of Letters Three

I know a word of letters three. Add two, and fewer there will be

Few.

Posted in Riddles

Something Dark Inside

Comes as wooden as a tree,
Covered in paint, don’t you see,
Makes you laugh, or run and hide,
For it has something dark inside.

A pencil. It’s wooden, is covered in paint and the output of a pencil in the form of writing or art can make you laugh or cry. And graphite is the dark part inside.

Posted in Riddles

A City in the Twilight

Half-way up the hill, I see thee at last, lying beneath me with thy sounds and sights — A city in the twilight, dim and vast, with smoking roofs, soft bells, and gleaming lights.

The Past (Longfellow).

Posted in Riddles

No Eyes But Once Could See

I do not have eyes but I once could see. I used to have thoughts but now I’m empty.

A skull.

Posted in Riddles

Spell check

Which word is always spelled wrong?

The word “wrong”.

Posted in Brain Teasers

Wait 27 Days Or See It Every Day?

You could wait 27 days or you could see it everyday. What is it?

The moon. Even though the true moon cycle is about 29.5 days, it takes 27 days, 7 hours, and 43 minutes for our Moon to complete one full orbit around Earth. Thus you can see the full moon every 27 days or you can moon yourself every day in the mirror. Not that you’d want to. Does anyone moon themselves? Can’t say as I’ve ever had the “pleasure”.

Posted in Riddles

Mario’s Racing Grandma

Mario is testing out a new car at the racetrack. His grandmother took it for a mile lap and averaged 30mph. How fast does Mario have to drive in the second lap to average 60mph for the two miles?

90mph is an alluring answer, but it’s impossible. At 90mph the second lap would take 40 seconds. If Grannie’s first lap at 30mph took 2 minutes, traveling 2 miles in 2 minutes and 40 seconds is an average speed of 45mph. Traveling an average speed of 60mph for 2 miles would take 2 minutes and since the grandma’s lap took all of those 2 minutes, even if Mario could break the sound barrier he wouldn’t be able to average 60mph.

Posted in Brain Teasers