1. Brain Teaser 1 www.mathsrevision.com He was a widower for 25 years. !
A 30 year old man married a 25 year old woman.
She died at age 50 and her husband was so
devastated that he cried for years. Ten years after
he stopped crying, he died. If he had lived to be 80.
How many years was he a widower?
He was a widower for 25 years. !

2. Jennifer is fifteen, in a system that awards
Brain Teaser 2
If Susan is 10, Arabella is 20, and Jim
and Neal are both 5, but Richard is 10.
How much is Jennifer by the same system?
Jennifer is fifteen, in a system that awards
five for each syllable.

3. Brain Teaser 3 If 2 hours ago it was as long after
one o'clock in the afternoon as it was before
one o'clock in the morning.
What time would it be now?
Nine o'clock. Since there are 12 hours between
the 2 times and  half of that time is six, then the
halfway mark would have to be 7 o'clock. If it were
7 o'clock, two hours ago, the time would now  be
nine o'clock.

4. Brain Teaser 4
I am eight letters long - " "  My 1234 is an atmospheric condition.  My supports a plant.  My 4567 is to appropriate.  My 45 is a friendly thank-you.  My 678 is a name. 
Q: What word am I?
MISTAKEN

5. Brain Teaser 5 Two boxers are in a boxing match
(regular boxing, not kick boxing).
The fight is scheduled for 12 rounds
but ends after 6  rounds, after one boxer
knocks out the other boxer. Yet no man  throws a punch.
How is this possible? 
They are female boxers.

6. Brain Teaser 6 Two mothers and two daughters were fishing.
They managed to catch  one big fish,
one small fish and one fat fish. Since only
three fish were caught.
How is it possible that they each
took home a fish?
The fishing party consisted of three people.
A grandmother, a mother, and a daughter.
The mother is both a mother and a  daughter. 

7. Simply push the cork into the bottle
Brain Teaser 7
If you were to put a coin into an empty
bottle and then insert a cork into the neck
How could you remove the coin without taking out the cork or breaking the bottle?
Simply push the cork into the bottle
and shake the coin out. 

8. What is at the beginning of eternity,
Brain Teaser 8
What is at the beginning of eternity,
the end of time,
the  beginning of every end
and the end of every place?
"e"

9. Brain Teaser 9 A snail is at the bottom of a well 30 feet
deep. It crawls up 3 feet each day, but at
night, it slips down 2 feet.
How long  does it take for the snail
to crawl out the well?
28 days. Once it reaches the top,
it does not slip down 2 feet. 

10. Brain Teaser 10 A boy leaves his house one summer day
and began to run  into the woods to his
grandmother's house which is on the other  side of the woods. It should also be known
that the boy reached  his grandmother's house.
How far did the boy run into the woods?
Halfway. Because once you reach the middle, you are then running out of the woods. 

11. Brain Teaser 11 www.mathsrevision.com
You want to send a valuable object to a friend.
You have a box  which is more than large enough
to contain the object. You have several locks with keys. The box has a locking ring which is more than large enough to have a lock attached. But your friend does not have the key to any lock that you have. Note that you cannot send  a key in an unlocked box, since it might be copied.
How is this done?
Attach a lock to the ring. Send it to her. She attaches her own lock and sends it back. You remove your lock and send it back to her. She removes her lock.

12. and a 7-minute egg timer. You want to measure 9 minutes.
Brain Teaser 12
You have two egg timers
a 4-minute egg timer
and a 7-minute egg timer.  You want to measure 9 minutes.
How do you do it?
Start both egg timers. When the 4-minute timer runs out, turn it over (4 minutes elapsed). When the 7-minute timer runs out, turn  it over (7 minutes elapsed). When the 4-minute timer runs out this time (8 minutes elapsed), the 7-minute timer has been running for 1 minute. Turn it over once again. When it stops, 9 minutes have  elapsed.

13. If there are fifteen crows on a fence
Brain Teaser 13
If there are fifteen crows on a fence
and the farmer shoots a  third of them.
How many are left?
None
they all flew away with noise of the gun.

14. The Lone Ranger rode into town on Friday.
Brain Teaser 14
The Lone Ranger rode into town on Friday.
He stayed 5 consecutive   days and left on Friday.
How could this be? 
Friday was the name of his horse.

15. None. A hole only has air in it, no dirt.
Brain Teaser 15
How much dirt is in a hole that is 3 ft deep
and 6 inches in diameter? 
None. A hole only has air in it, no dirt. 

16. How many times can you subtract After the first calculation,
Brain Teaser 16
How many times can you subtract
the number 5 from 25?
Once.
After the first calculation,
you will be subtracting 5 from 20,  then 5 from 15, and so on.

17. Brain Teaser 17 There is a man that lives on the top floor
of a very tall  building.  Everyday he gets
the elevator down to the ground floor to leave the building to go to work.  Upon returning from work though, he  can only travel half way up in the lift and has to walk the rest of the way, unless it's raining!  WHY?
The man was a dwarf and couldn't reach top lift buttons except with an umbrella.

18. Brain Teaser 18 A man is wearing black. Black shoes, socks,
trousers, jumper,  gloves, and balaclava. 
He is walking down a black street with all the
street lamps off.  A black car is coming
toward him  with its lights off too, but
somehow manages to stop in time.  How  did the driver see the man?
It was day time.

19. Brain Teasers 19 Is half of two plus two equal to two or three?
Three. It seems that it could almost be either, but if you follow the mathematical orders of operation, division is performed before addition. So... half of two is one. Then add two, and the answer is three.

20. How would you rearrange the letters
Brain Teaser 20
How would you rearrange the letters
in the words “ new door” to make one word?
There is only one correct answer. 
One Word!