#11 - Hard Math Riddle

Take 9 from 6, 10 from 9, 50 from 40 and leave 6.

How Come ??

SIX - 9 (IX) = S
9 (IX) - 10 (X) = I
40 (XL) - 50 (L) = X
===>SIX

#12 - Puzzle In A Puzzle

What are the next two letters in the following series and why?
W A T N T L I T F S _ _
*Hint: Check Puzzle Title

Puzzle In A Puzzle

The letters are the first letters of the words in the question. Thus, the next two letters are A and W.

#13 - Eight 8 Add Puzzle

Can you add eight 8's together so they add up to an even one thousand ?

Eight 8 Add Puzzle

888+88+8+8+8=1000

#14 - Complete The Equation

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

Complete The Equation

Draw a line on the first plus sign. This turns it into a 4! The equation then becomes true: 545+5=550.

#15 - Two Door Riddle

You find yourself in a strange place guarded by two guards.One of the guard always say truth while other always lies.You don't know the identity of the two.You can ask only one question to go out from there. What should you ask?

Two Door Riddle

If you ask the guard who always tells the truth, he would tell you the other guard would point you to the door of death. If you ask the guard who always lies, he would tell you the opposite door of the truth-telling guard and point you to the door of death. In either case, both guards will point to the door of death so you should choose the other one.

#16 - Trick Riddle

What is the longest word in the dictionary

Trick Riddle

Smiles (there is a mile between the two S's)

#17 - Fun Math Puzzle

Baseball bat and ball cost $50. If the bat cost $49 more than the ball, what is the cost of each

Fun Math Puzzle

bat $49.50, ball $0.50

#18 - Tricky Maths Problem

I drive at an average speed of 30 miles per hour to the railroad station each morning and just catch my train. On a particular morning there was a lot of traffic and at the halfway point I found I had averaged only 15 miles per hour. How fast must I drive for the rest of the way to catch my train?

Tricky Maths Problem

The train is just about to leave the station and there is no way I will be able to catch it this time.

#19 - Monty Hall Problem Puzzle

The host of a game show, offers the guest a choice of three doors. Behind one is a expensive car, but behind the other two are goats.
After you have chosen one door, he reveals one of the other two doors behind which is a goat (he wouldn't reveal a car).

Now he gives you the chance to switch to the other unrevealed door or stay at your initial choice. You will then get what is behind that door.

You cannot hear the goats from behind the doors, or in any way know which door has the prize.

Should you stay, or switch, or doesn't it matter?

Monty Hall Problem Puzzle

You better switch!

Your first choice has a 1/3 chance of having the car, and that does not change.
The other two doors HAD a combined chance of 2/3, but now a Goat has ben revealed behind one, all the 2/3 chance is with the other door.

#20 - Most Famous Maths Puzzle

I can prove why 1 = 2

* Lets say y = x
* Multiply through by x xy = x2
* Subtract y2 from each side xy - y2 = x2 - y2
* Factor each side y(x-y) = (x+y)(x-y)
* Divide both sides by (x-y) y = x+y
* Divide both sides by y y/y = x/y + y/y
* And so... 1 = x/y + 1
* Since x=y, x/y = 1 1 = 1 + 1
* And so... 1 = 2

How is this possible ?

Most Famous Maths Puzzle

Step 5 is invalid, because we are dividing by (x-y), and since x=y, we are thus dividing by 0. This is an invalid mathematical operation (division by 0), and so by not following basic mathematical rules