Lending Money to Darlene

Franklin lent Darlene as much money as she already had, then she spent $10. The next day, Franklin lent her as much money as she now had and again, she spent $10. On the third day Franklin once again lent her as much money as she now had and she spent $10, leaving her broke. How much money did Darlene start with?

$8.75
You may have been tempted to guess $30 because $10 is spent three times, but that would mean she would have had $60 ($30 lent plus the $30 she already had), and $50 after spending $10. The rest of the numbers end up at higher than zero, so we know it has to be less than $30. Even starting at $10 leaves Darlene with $10 on the third day. Starting with $8.75 works out as follows.

Day 1: $8.75 (lent) + $8.75 (already had) – $10 (spent) = $7.50 (remaining)
Day 2: $7.50 + $7.50 – $10 = $5
Day 3: $5 + $5 – $10 = $0

Posted in Brain Teasers

Remove Six Letters

Remove six letters from this sequence to reveal a familiar English word.

BSAINXLEATNTEARS

The familiar English word that remains is BANANA after removing the phrase “SIX LETTERS”.

Posted in Riddles

The Potato Paradox

Fred brings home 100 pounds of potatoes, which (being purely mathematical potatoes) consist of 99 percent water. He then leaves them outside overnight so that they consist of 98 percent water. What is their new weight?

50 pounds.

100 lb of potatoes with 99% water weight means there’s 99 lb of water and 1 lb of solids, a 1:99 ratio.

If the water decreases to 98%, then the solids account for 2% of the weight. The 2:98 ratio reduces to 1:49. Since the solids still weigh 1 lb, the water must weigh 49 lb for a total of 50 lbs for the answer.

Read more at the Potato Paradox wikipedia page.

Posted in Brain Teasers

Having and Sharing

If you have it, you want to share it.
If you share it, you don’t have it.

What is it?

A secret.

Posted in Riddles

Five Letters Sound Like Six When Pronounced

What five-letter word sounds like six letters when pronounced?

Cello. The pronunciation of c is ‘ch’, making it sound like the word has 6 letters.

Posted in Riddles

5 25 325 4325

Given

1 = 5
2 = 25
3 = 325
4 = 4325

What does 5 equal?

54325. Rather than being a mathematical solution, the answer is derived by prepending (putting in front of) the value on the left side of the equation with the previous answer. So for 3 you take 25, the previous answer, and put 3 in front, giving you 325. Then you put 4 in front to get 4325 and lastly, put 5 in front to get 54325.

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A Group of Three

I give you a group of three. One is sitting down, and will never get up. The second eats as much as is given to him, yet is always hungry. The third goes away and never returns.

Stove, fire, smoke.

Posted in Riddles

A Blood Red Shroud

The thunder comes before the lightning,
And the lightning comes before the cloud,
The rain dries all the land it touches,
Wrapping the earth in a blood red shroud.

What am I?

A volcano.

Posted in Riddles

A Neck and No Head

What has a neck and no head, two arms but no hands?

A shirt (or sweater, jacket, etc).

Posted in Riddles

250 Lbs Across the River

Two boys weighing 50 pounds each and their older brother weighing 100 pounds wish to cross a river. Their boat will only hold 100 pounds. How can they all cross the river in the boat?

Two 50lb boys cross, one comes back.
100lb boy crosses, other 50lb boy returns
Both 50lb boys cross.

Posted in Brain Teasers