Messy Math

What is the answer to this problem?

48 / 2(9 + 3) = ?

It depends. Usually, math has one right answer, but in this case, the order of operations can get a little quirky.

There are two ways to solve this. First, like so:
48 / 2 × (9 + 3) = ?
48 / 2 × (12) = ?
24 × 12 = 288

But another, arguably valid way is:
48 / 2 × (9 + 3) = ?
48 / 2 × (12) = ?
48 / 24 = 2

Thanks to KnowYourMeme for providing a great overview on this one. Math StackExchange has more discussion.

Posted in Brain Teasers

Find The Hidden Cities

Wallace died a wealthy, if somewhat odd, man without any living relatives. He left his money in four different cities for the first four people who could find it. The only clue he left was this poem:

Do not go solo,
Pairs up with a friend,
Though I hasten to add,
I’ll avenge my end.

What are the four cities?

Anagrams of four cities can be found in the poem.

Oslo (solo)
Paris (pairs)
Athens (hasten)
Geneva (avenge)

Posted in Brain Teasers

O T T F F

What letter comes next?

O T T F F S S

E (one, two, three, four, five, six, seven eight)

Posted in Brain Teasers
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White, Round Not Always Around

I’m white, I’m round, but not always around. Sometimes you see me, sometimes you don’t. What am I?

The moon.

Posted in Riddles

Working With Something In Its Eye

What always works with something in its eye?

A needle. Thread goes in the eye of the needle when you sew. If you sew…

Posted in Riddles

You Are My Brother

You are my brother but I am not your brother. Who am I?

Your sister.

Posted in Riddles

Always Flying, Never Tired

Always flying,
never tired,
dreamed of, dreaded,
and admired.

Cloud.

By Sef Daystrom

Posted in Riddles

The Bookworm

A bookworm eats from the first page of an encyclopedia to the last page in a straight line. The encyclopedia consists of ten 1000-page volumes and is sitting on a bookshelf in the usual order. Not counting covers, title pages, etc., how many pages does the bookworm eat through?

        __                             __
      B|  |                           |  |F
      A|1 |...........................|10|R
      C|  |                           |  |O
      K|  |                           |  |N
       |__|                           |__|T
      -------------------------------------

On a book shelf the first page of the first volume is on the “inside”, so the bookworm eats only through the cover of the first volume, then 8 times 1000 pages of Volumes 2 – 9, then through the cover to the 1st page of Vol 10 for a total of 8,000 pages.

Note: The question asks how many pages, not how many sheets of paper.

Posted in Brain Teasers

Four Gallons From Two Buckets

You have two buckets. One holds exactly five gallons and the other three gallons. How can you measure exactly four gallons of water into the five gallon bucket?

Assume you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.

  1. Fill the 3-gallon bucket.
  2. Pour the 3 gallons of water into the 5-gallon bucket
  3. Fill the 3-gallon bucket again.
  4. Fill up the 5-gallon bucket with the 3-gallon bucket, leaving you with 1 gallon left in the 3-gallon bucket.
  5. Empty out the 5-gallon bucket.
  6. Pour the remaining 1 gallon of water from the 3-gallon bucket into the 5-gallon bucket.
  7. Fill the 3-gallon bucket.
  8. Pour the 3 gallons of water from the 3-gallon bucket into the 5-gallon bucket leaving you with 4 gallons of water in the 5-gallon bucket.

Alternate solution:

  1. Fill up the 5 gallon bucket
  2. Pour it into 3 gallon bucket, leaving 2 gallons
  3. Empty out the 3 gallon bucket
  4. Pour the 2 gallons in the 5 gallon bucket into the 3 gallon bucket
  5. Fill up the 5 gallon bucket and pour it into the 3 gallon bucket until it’s full, leaving 4 gallons in the 5 gallon bucket.
Posted in Brain Teasers

The Case of the Missing Matchstick

Chuck and Ruby were going to meet at a hotel for their anniversary dinner, but Ruby didn’t show. Chuck was angry and left her a passive aggressive message on their kitchen table in the form of fifteen matchsticks spelling “hotel” and went to bed. When Ruby got home and saw the matchsticks, she removed one and went to bed. When Chuck woke up the next morning and saw Ruby’s new message, he realized his mistake. Which stick did Ruby remove and what was the new message?

Matchsticks

Ruby had removed the top of the T and the new message could be seen upside down from where Chuck sat at his breakfast of sadness and anger. What he saw was 7 3 1 0 4, or 7/31/04, the date of their anniversary. In his excitement, Chuck had gone to the restaurant a day early, on July 30th. All was forgiven by both parties and Chuck and Ruby had a wonderful dinner together. They also promised to buy a whiteboard for the kitchen so they wouldn’t have to use matchstick messages ever again.

Posted in Brain Teasers