The Prime Number Riddle
Two hundred people in an auditorium are asked to think of a single digit number from 1 to 9 inclusive and write it down. All those who wrote down a prime number are now asked to leave. Ninety people remain behind in the hall. How many of these are expected to have written down an odd number?
Hint: Remember that 1 is not a prime number.
Those that remain behind must have written {1,4,6,8,9} and from this only {1,9} are odd. The probability of an odd number is thus 2/5.
Expected number of odds is 2/5 * 90 = 36 Did you answer this riddle correctly?
YES NO
Expected number of odds is 2/5 * 90 = 36 Did you answer this riddle correctly?
YES NO
Sad Nose Riddle
Hint:
A Ninja Under The Weather
Hint:
The Twelve Inch Nose Riddle
Hint:
Ninja At The Doctor
Hint:
Naughty Eyeball Riddle
Hint:
The Number Four Be Half Of Five Riddle
Hint:
IV, the Roman numeral for four, which is “half” (two letters) of the word five. Did you answer this riddle correctly?
YES NO
YES NO
The Correct Number Riddle
Hint:
121
Explanation
Tables consist of squares of the number from 4 to 12.
11^2 = 121. Did you answer this riddle correctly?
YES NO
Explanation
Tables consist of squares of the number from 4 to 12.
11^2 = 121. Did you answer this riddle correctly?
YES NO
Find Those Missing Numbers Riddle
In the attached figure, you can find two missing numbers. Can you analyze the pattern and find those missing numbers?
Hint:
The number missing on the left is 8 and the one on right is 7.
Explanation:
The pattern:
The number in the center of triangle is the square root of the sum of the numbers sitting outside on the corners.
Thus,
10 + 22 + 4 = 36
Square Root of 36 = 6
In the same manner:
10 + 42 + 12 = 64
Square Root of 64 = 8
12 + 22 + 15 = 49
Square Root of 49 = 7 Did you answer this riddle correctly?
YES NO
Explanation:
The pattern:
The number in the center of triangle is the square root of the sum of the numbers sitting outside on the corners.
Thus,
10 + 22 + 4 = 36
Square Root of 36 = 6
In the same manner:
10 + 42 + 12 = 64
Square Root of 64 = 8
12 + 22 + 15 = 49
Square Root of 49 = 7 Did you answer this riddle correctly?
YES NO
I Am A 3 Digit Number Between 400 And 800 Riddle
I am a 3 digit number between 400 and 800. My digits add up to 15. My ten's digit is twice my hundreds digit. What number am i?
Hint:
If A Door Number Fitter Riddle
In a new hotel containing 100 rooms, Tom was hired to paint the numbers from 1-100 on the doors. How many times will Tom have to paint the number 8?
Hint:
The answer is 20. Many people have been guessing anywhere from 9 to 19, but the correct answer is 20. Did you answer this riddle correctly?
YES NO
YES NO
Head Of The Facility Riddle
Hint:
Naming A Casket Riddle
Hint:
Making Dirty Money
Im to make dirty money youll probably wash;
Im put over your shoes like a snow-day galosh;
The loud clamorous noise you might hear at a mosh;
And the hand-held equipment for tennis or squash.
Who am I?
Im put over your shoes like a snow-day galosh;
The loud clamorous noise you might hear at a mosh;
And the hand-held equipment for tennis or squash.
Who am I?
Hint:
Two Solid Metal Pillars
You are standing on the top one of two solid metal pillars. They are both exactly one kilometer apart from each other and they both stand one kilometer high. There is absolutely nothing around these pillars, but you have one small twig, one small rock and an unlimited supply of rope. Using only the materials named, how can you get from the top of the pillar that you are on to the top of the other pillar?
Hint:
The twig and the rock were simply distractions used to divert you from the real answer. Forget I ever mentioned them. All you need to do is fill the space between you with enough rope that it makes a pile so big that you can walk across it to the other pillar (remember I said you had an unlimited supply of rope). Did you answer this riddle correctly?
YES NO
YES NO
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