Ewa kept tossing a fair coin until the first head appeared. Let the total number of tosses be N. Igor was then asked to guess N by asking Ewa an efficient sequence of yes-no questions such that the average number of questions is minimized.

What is the form of the questions that Igor asked? And what’s [...]

Tags:

Coin flips,

Statistics
Fish , 1/3 of its body in mud ,1/4 of its body in water .. and 30 cm of its body out of water -in the surface of the water- … how tall the fish is?

Hi guys, long time no see.

Here i give two infinite series:

1) What are all the possible values of the following series?

1-1+1-1+1-1+1-1+1-1+1……to infinity

2) What are all the possible values of ‘x’ for which the following series converges.

((((((x-2)²-2)²-2)²-2)²-2)²-2)²……..

Tags:

Logic,

Mathemagic
What shape completes the bottom line?

triangle pentagon square

square hexagon hexagon square

pentagon hexagon hexagon hexagon square triangle

hexagon octagon octagon octagon octagon ?????

- Karl Sharman

What is the smallest integer that ends with a 3 and that when that 3 is moved from the end to the beginning, makes the number 3 times as large.

i.e. I want something like 312 = 3*123 (which obviously doesn’t work).

Tags:

Mathemagic
There is a man in a room, with no windows doors, each wall, floor and ceiling is 6inches of concrete. All he has is a mirror with him. How does he get out? HINT: think outside the box.

what is greater than god. more evil than the devil. rich people need it. poor people have it. if you eat it you will die.

(1) 54 C P w J

(2) 13 P at L S

(3) 15 M on D M C

(4) 29 D in F in L Y

(5) 80 F S

(6) 10 P B

(7) 100 N in BT

(8) 28 N of D in L C

(9) 5 P on P

[...]

What is the probability that if you randomly chose any three squares on a chess board, they would form a continuous diagonal? No dudes, you don’t hold a chess board in your hands to solve this one. Just think simply.

mohamed want to reach the bus station because his care broke down in some where..in his way there were 2 ways one on left ,one on right and small house in between ,he dunno the right way , in this house there were identical twins ,one of them always tell lies the other just tell [...]