Riddles and Brain Teasers

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) = 16If 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.

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

Often Talked Of But Never Seen

Often talked of, never seen,
Ever coming, never been,
Daily looked for, never here,
Still approaching, coming near,
Thousands for it’s visit wait,
But alas for their fate,
Tho’ they expect me to appear,
They will never find me here.

Show the answer »

Tomorrow.

Posted in Brain Teasers

I Wave But Never Say Goodbye

I wave my hands at you,
But I never say goodbye.

You’re always cool with me,
Even cooler when I’m high.

What am I?

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An electric fan

Posted in Riddles

Tagged with What am I?

The Barber of Seville

The Barber of Seville shaves all men living in Seville.
No man living in Seville is allowed to shave himself.
The Barber of Seville lives in Seville.

Who shaves the Barber of Seville?

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Nobody. The Barber of Seville is a woman. Female barbers are rare, but they exist.And for more fun with barbers, check out the Barber paradox.

Nobody. The Barber of Seville is a woman. Female barbers are rare, but they exist.

And for more fun with barbers, check out the Barber paradox.

Posted in Brain Teasers

Living to Six

How can you cross out four letters from the word LIVING to leave six remaining?

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Cross out LING, leaving you with VI, or 6 in Roman numerals.

Posted in Brain Teasers

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.

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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.

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