#11 - 5 Children Problem
Lee's parents have five children, the names of the first four are La, Le, Li, and Lo.
What's the name of the fifth child?
of-course Lee
#12 - An interesting paragraph Problem
Study this paragraph and all things in it. What is vitally wrong with it? Actually, nothing in it is wrong, but you must admit that it is most unusual. Don't just zip through it quickly, but study it scrupulously. With luck you should spot what is so particular about it and all words found in it. Can you say what it is? Tax your brains and try again. Don't miss a word or a symbol. It isn't all that difficult?
no "e"
#13 - Barbershop Problem
A traveller arrives in a small town and decides he wants to get a haircut. There are only two barbershops in town - one on East Street and one on West Street. The East Street barbershop is a mess, and the barber has the worst haircut the traveller has ever seen. The West Street barbershop is neat and clean, its barber's hair looks as good as a movie star's.
Which barbershop does the traveller go to for his haircut, and why?
The traveler goes to have his hair cut at the barbershop on East Street. He figures that since there are only two barbershops in town the East Street barber must have his hair cut by the West Street barber and vice versa. So if the traveler wants to look as good as the West Street barber (the one with the good haircut), he'd better go to the man who cuts the West Street barber's hair - the East Street barber.
By the way, the reason the West Street barbershop is so clean and neat is that it seldom gets cut.
#14 - Riddle Problem
The part of the bird
that is not in the sky,
which can swim in the ocean
and always stay dry.
A Shadow
#15 - Game Show Problem(Old One)
You are on a game show and there are three doors. The presenter tells you that behind one of doors there is a car and behind the other two are goats, if you pick the car you win it. After you have picked a door the presenter opens a different door with a goat behind it, he then gives you the chance to change what door you open, what should you do?
You want to change your decision. The initial decision has a 1 in 3 shot of being correct. Changing to the alternate door has a 2/3 chance of being correct. Think of it this way, if your initial pick is not the car (which has a 2/3 probability) then it must be that the alternate unopened door IS the car.
This is also known as the Monty Hall Problem
#16 - What is the spead of train Problem
In a Tunnel 1 KM long. Two friends are standing at 600m inside the Tunnel (i.e. 600m from 1 side and 400m from other).Suddenly they heard the whistle of a train.Both started to run on opposite direction at spead of 10 KM/Hr.Both of them just survived.
What is the speed of train?
Assume the whistle sound doesn't take time to travel.
600m (0.6km) takes 0.6 / 10 = .06 (hr)
400m (0.4km) takes 0.4 / 10 = .04 (hr)
Since both of them "JUST" survived. That means the train enter the tunnel at 0.04 hr and exit tunnel at 0.06 hr. That means it takes the train 0.06 - 0.04 = 0.02 hr to travel 1 km.
Therefore, the speed of the train is 1km / 0.02 hr = 50 km/hr
#17 - Magic Belt Problem
A magic wish-granting rectangular belt always shrinks to 1/2 its length and 1/3 its width whenever its owner makes a wish. After three wishes, the surface area of the belt's front side was 4 cm2.
What was the original length, if the original width was 9 cm?
Let the original lenght = x cm.
and the given width = 9 cm.
1st wish:
lenght =x/2 cm; width =9/3=3 cm;
2nd wish:
lenght =x/4 cm; width =1 cm;
3rd wish:
lenght =x/8 cm; width =1/3 cm;
After three wishes:
The given Surface area A (say) = 4 cm2;
Surface area A = length * width;
4 cm2 =(x/8 )*(1/3) cm2;
x = 4 *24= 96 cm;
The original length x= 96 cm;
#18 - Riddle Problem
What goes up and down but doesn't move?
STAIRS
Also sensex Temperature and Blood pressure.
#19 - Get Gold Coin Problem
Imagine there are 3 coins on the table: gold, silver, and copper. If you make a truthful statement, you will get one coin. If you make a false statement, you will get nothing.
What sentence can guarantee you getting the gold coin?
"You will give me neither copper nor silver coin." If it is true, then I have to get the gold coin. If it is a lie, then the negation must be true, so "you give me either copper or silver coin", which would break the given conditions that you get no coin when lying. So the first sentence must be true
#20 - Dare to guess what day it is Problem
In one small town, there is a liar who lies on six days of the week. But on the seventh day he always tells the truth. He made the following statements on three successive days:
Day 1: 'I lie on Monday and Tuesday.'
Day 2: 'Today, it's Thursday, Saturday, or Sunday.'
Day 3: 'I lie on Wednesday and Friday.'
What day does the guy tell the truth?
He speaks the truth on Tuesdays.
The assertions of Day 1 and Day 3 can't both be true.
Else there would be two truth days: Day 1 and Day 3.
So he cannot lie on all four days mentioned: M T W and F.
The truth day is M T W or F.
The assertions of Day 1 and Day 3 also can't both be false.
Else the truth day would be M or T and also would be W or F, making two truth days.
The truth day is Day 1 or Day 3.
The assertion of Day 2 can't be true.
Else there would be two truth days: Day 2 and Day 1 or Day 3.
Negating Day 2's statement, we see that
Day 2 is M, T, W or F.
Day 2 can't be T or W.
Else Day 1 would be M or T, on which days he claims to lie. A paradox.
Day 2 can't be F.
Else Day 1 would be Th on which he claims to lie M T, and Day 3 would be Sat on which he claims to lie W F.
This makes two truth days: Day 1 or Day 3 [Thu or Sat] and M, T, W or F.
Day 2 is M.
The truth day is Sun or T.
The truth day can't be Sun.
Else, on Day 3 he lies about lying on both W and F, creating two truth days: Sun and W or F.
The truth day is T.
Check:
Day 1 [Sun] I lie on M T. [a lie - he speaks truth on T] - OK
Day 2 [Mon] It's Th, Sat or Sun. [a lie - it's M] - OK
Day 3 [Tue] I lie on W F. [the truth - he does lie on those days] - OK