All Words From Nine Letters to One

What 9-letter word can have a letter removed to make a new word and repeat the process until a single letter remains?

startling
starting
staring
string
sting
sing
sin
in
i

Posted in Brain Teasers

Mario’s Racing Grandma

Mario is testing out a new car at the racetrack. His grandmother took it for a mile lap and averaged 30mph. How fast does Mario have to drive in the second lap to average 60mph for the two miles?

90mph is an alluring answer, but it’s impossible. At 90mph the second lap would take 40 seconds. If Grannie’s first lap at 30mph took 2 minutes, traveling 2 miles in 2 minutes and 40 seconds is an average speed of 45mph. Traveling an average speed of 60mph for 2 miles would take 2 minutes and since the grandma’s lap took all of those 2 minutes, even if Mario could break the sound barrier he wouldn’t be able to average 60mph.

Posted in Brain Teasers

Harvest Though No Grain

I harvest you, though you’ve no grain,
I reap you in the wind and rain,
You bleed not but your soft meat
And nectar makes a sweetest treat.
What am I?

A clam or oyster. You harvest clams or oysters on the beach or go diving, and the beach is often windy and rainy. Neither bleeds but are known for having, soft, slimy meat, and people often drink the “clam nectar” or “oyster juice”.

Thanks to Helena for this submission

Posted in Riddles
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A Seed of Three Letters

I am a seed, three letters in the name,
Take away two and I sound quite the same.

What am I?

Pea.

Posted in Riddles

Mysterious Math

This problem can be solved by preschool children in five to ten minutes, by programmers in an hour and by people with higher education…well, check it yourself.

8809 = 6
7111 = 0
2172 = 0
6666 = 4
1111 = 0
3213 = 0
7662 = 2
9313 = 1
0000 = 4
2222 = 0
3333 = 0
5555 = 0
8193 = 3
8096 = 5
1012 = 1
7777 = 0
9999 = 4
7756 = 1
6855 = 3
9881 = 5
5531 = 0
2581 = ?

What is the missing number and why?

Two. The number is how many closed circles there are in the 4 digits. 0, 6 and 9 each have one, 8 has 2.

Posted in Brain Teasers

Mental Calculations

Perform this calculation in your head, mentally adding the numbers as quickly as you can. Start with 1000 and add 40. Now add 1000. Add 30 to that, then add another 1000. Now add 20 to that result. Add another 1000 and finally, add 10 to that. What is the total?

4,100. If you got 5,000 you’re not alone. 96% of test subjects get the wrong answer.

Posted in Brain Teasers

Can’t Keep It Until You’ve Given It

You can’t keep this until you have given it.

A promise (or your word).

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

Ties One Another

What ties one to another and is closest to the heart?

A wedding ring.

I know, this is nearly a duplicate with What Holds Two People Together.

Posted in Riddles

Serve Many But They Forget About Me

I serve many, confirmed by how healthy those I serve are. Yet after they’re successful they forget about me. It’s true, sometimes I hit them and they’re often bloody, but they don’t mind.

What am I?

A doctor (more specifically, an obstetrician) or a midwife. They deliver thousands of healthy babies but they are soon forgotten. Sometimes they smack the baby on the butt to clear the airway, and newborn babies can have blood on them from the placenta being pulled from the walls of the uterus or from an episiotomy.

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