What Digit Does Each Letter Represent?

This is what you know:

1. Each letter represents a different digit from 1 to 9
2. The total of each row is 17.
3. (B × B) + B + F = A
4. C × F = EF (a 2-digit number, not their product)

A B C
D E F

What digit does each letter represent?

A = 7
B = 1
C = 9

D = 8
E = 4
F = 5

A + B + C = 17
D + E + F = 17
B2 + B + F = A
C × F = EF

To begin with, B has to be a 1 or 2 or else A wouldn’t be a single digit. Plug in B = 2, gives you 6 + F = A, meaning F and A can only be (1,7) or (3,9). To get 17, C would have to be 8 or 6, but those values don’t work for C × F = EF. So B must be 1.

2 + F = A means F and A can be (2,4), (3,5), (4,6), (5,7), (6,8) or (7,9). To get 17 on the top row, the only option that leaves C as a single digit is F = 5 and A = 7.

C × F = EF
9 × 5 = 45, so E = 4 and D = 8 to make the second row equal to 17.

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

I Make Memories That Last a Lifetime

I make memories that last a lifetime,
Without me you’ll be miserable,
If you miss me you can gourge and it’s okay.
Some say I am naturally split in two.

What am I?

Sleep. It’s the time your mind organizes memories and knowledge. Sleep deprivation is miserable (as you well know if you’ve experienced it). If you miss a few nights of sleep, you can sleep more to catch up with no problems. And some believe that segmented sleep, where you sleep, wake for an hour, then go back to sleep, was the dominant form of sleep before the Industrial Revolution.

Posted in Riddles
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Forward I’m Heavy

Forward I’m heavy, but backwards I’m not. What am I?

Ton.

Posted in Riddles

Seemingly Simple Math

What is the answer to this math problem:

8 ÷ 2 (2 + 2)

16 or 1, depending.

According to PEMDAS, parentheses come first: 8 ÷ 2 (4)

Then, even though multiplication is first in PEMDAS, you go left to right: 4 (4) = 16

If you got 1, you’re in good company. That’s what I got at first too but most calculators I’ve tried get 16.

I found this at Popular Mechanics and the debate continues online.

Posted in Brain Teasers

1 2 3 4 5 6 7 8 9 = 100

This equation is incomplete: 1 2 3 4 5 6 7 8 9 = 100

One way to make it accurate is by adding seven plus and minus signs, like so.

1 + 2 + 3 – 4 + 5 + 6 + 78 + 9 = 100

How can you do it using only 3 plus or minus signs?

123 – 45 – 67 + 89 = 100

Posted in Brain Teasers

Represent The Alphabet

What word or expression does this represent?

ABCDEFGHIJKLMNOPQRSTVWXYZ

Missing you (U).

Posted in Brain Teasers

Shorter Than My Four Siblings

Shorter than my four siblings,
but easily the strongest,
sometimes I wear a funny hat.

A Thumb.

By Sef Daystrom

Posted in Riddles

Greater Than God

It is greater than God and more evil than the devil. The poor have it, the rich need it and if you eat it you’ll die. What is it?

Nothing. Nothing is greater than God, nothing is more evil than the devil, the poor have nothing, the rich need nothing and if you eat nothing you’ll die.

Posted in Riddles

Stocking the Shelves

Alfred and Bill are clerks at the local grocery store. Alfred can stock a shelf in 20 minutes, but Bill is new and takes 30 minutes. How long would it take for them to stock a shelf together?

Working together they can stock a shelf at a rate of 1/20 + 1/30 (or 5/60) per minute. They’ll finish in 12 minutes

Posted in Brain Teasers