What One One One Represents

What do the following numerals represent?

11111121113122223222

The number of syllables in the numbers from one to twenty.

Posted in Brain Teasers

777, 888 and 999

You are given the numbers 777, 888 and 999. Using the numbers once and adding, subtracting, multiplying or dividing, how can you make 999?

(7 x 7 x 7) + (9 x 9 x 8) + ((9 – 8) x 8) = 999
(77 + 7) + 888 + (9 + 9 + 9) = 999

If other operators were allowed, another solution would be 999 modulo (888 x 777). I’m sure there are more solutions.

Posted in Brain Teasers

amid eerie nighed won spawn

What phrase do these words sound like when rearranged?

amid eerie nighed won spawn

“Won spawn amid nighed eerie” sounds like, “Once upon a midnight dreary”, from The Raven by Edgar Allan Poe.

Posted in Brain Teasers

Lying On Certain Days of the Week

Angel lies on Mondays, Tuesdays and Wednesdays but tells the truth the rest of the week.

Brenda lies on Thursdays, Fridays and Saturdays, but tells the truth every other day.

Angel says, “Yesterday I was lying.”

Brenda replies, “So was I.”

What day was it?

Thursday.

Putting the information in a table makes it easier to solve. We’ll use A for Angie, B for Brenda, T for truth and F (false) for lying.

 SMTWThFS
ATFFFTTT
BTTTTFFF

To begin with, there aren’t any days where both of them told the truth and lied the day before, so we know one of them must be lying.

So we have two options, either Angel is lying or Brenda is.

Option 1. Angel is lying.

In order for this to be the case, she needs to be lying today and telling the truth yesterday, so we need two days in a row with T F. And if Brenda is telling the truth, she would need two days with F T. That means we’re looking for two days that have

Angie:  T F
Brenda: F T

Option 2. Brenda is lying.

This is just the reverse of the above, so we need to find:

Angie:  F T
Brenda: T F

The only day that matches either of the two options is Thursday, and it’s option 2. Brenda is the liar.

Posted in Brain Teasers

The Most Impressive Boundary

The most impressive boundary’s not a wall.
It’s not a manufactured thing at all.
Moving towards it won’t reduce the gap
and nothing marks its presence on a map.

The horizon.

By Sef Daystrom

Posted in Riddles

Animals On the Ark

How many of each animal did Moses take on the ark?

None. Moses didn’t have an ark, Noah did (and yes, he took 2 of each animal).

Posted in Brain Teasers

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

Largest Product

Using all the digits from 1 to 7, what two numbers have the largest product? For example, 1234 x 567 = 699678 but you can do much better than that.

742 x 6531 = 4,846,002.

A similar problem can be found in L.A. Graham’s Ingenious Mathematical Problems and Methods with a range of 1 to 9, but the principle remains the same – the numbers with the smallest difference produce the largest product. You start out with the highest two digits, 7 and 6, then attach 5 and 4, putting the smaller of the two digits with the larger number, giving you 74 and 65. The next two highest digits are 3 and 2, giving you 742 and 653. Finally, you add the 1 to the lower number. Page 80 has the details of that solution.

Posted in Brain Teasers

Pitching On The Merry-Go-Round

Everly and I were playing on the merry-go-round at the local park. It was very large and we stood on opposite sides. As we spun the merry-go-round counter-clockwise, I threw a ball to Everly. Did the ball go to Everly, to the right or left of them?

Since the merry-go-round had moved while the ball was traveling to Everly the ball went to the right of them.

Posted in Brain Teasers

Forever Stuck

I can’t go right,
I can’t go left.

I’m forever stuck going only up and down.

What am I?

An elevator.

Posted in Riddles