The Magic Number Riddle
Multiply times 2
Add 6
Divide by 2
Subtract the first number you thought of
What is the number you came up with?
Hint:
The answer is 3
If you got a different number you did the math wrong Did you answer this riddle correctly?
YES NO
If you got a different number you did the math wrong Did you answer this riddle correctly?
YES NO
The 100 Seat Airplane
People are waiting in line to board a 100-seat airplane. Steve is the first person in the line. He gets on the plane but suddenly can't remember what his seat number is, so he picks a seat at random. After that, each person who gets on the plane sits in their assigned seat if it's available, otherwise they will choose an open seat at random to sit in.
The flight is full and you are last in line. What is the probability that you get to sit in your assigned seat?
The flight is full and you are last in line. What is the probability that you get to sit in your assigned seat?
Hint: You don't need to use complex math to solve this riddle. Consider these two questions:
What happens if somebody sits in your seat?
What happens if somebody sits in Steve's assigned seat?
The correct answer is 1/2.
The chase that the first person in line takes your seat is equal to the chance that he takes his own seat. If he takes his own seat initially then you have a 100% chance of sitting in your seat, if he takes your seat you have a 0 percent chance. Now after the first person has picked a seat, the second person will enter the plan and, if the first person has sat in his seat, he will pick randomly, and again, the chance that he picks your seat is equal to the chance he picks someone your seat. The motion will continue until someone sits in the first persons seat, at this point the remaining people standing in line which each be able to sit in their own seats. Well how does that probability look in equation form? (2/100) * 50% + (98/100) * ( (2/98) * 50% + (96/98) * ( (2/96) * (50%) +... (2/2) * (50%) ) ) This expansion reduces to 1/2.
An easy way to see this is trying the problem with a 3 or 4 person scenario (pretend its a car). Both scenarios have probabilities of 1/2. Did you answer this riddle correctly?
YES NO
The chase that the first person in line takes your seat is equal to the chance that he takes his own seat. If he takes his own seat initially then you have a 100% chance of sitting in your seat, if he takes your seat you have a 0 percent chance. Now after the first person has picked a seat, the second person will enter the plan and, if the first person has sat in his seat, he will pick randomly, and again, the chance that he picks your seat is equal to the chance he picks someone your seat. The motion will continue until someone sits in the first persons seat, at this point the remaining people standing in line which each be able to sit in their own seats. Well how does that probability look in equation form? (2/100) * 50% + (98/100) * ( (2/98) * 50% + (96/98) * ( (2/96) * (50%) +... (2/2) * (50%) ) ) This expansion reduces to 1/2.
An easy way to see this is trying the problem with a 3 or 4 person scenario (pretend its a car). Both scenarios have probabilities of 1/2. Did you answer this riddle correctly?
YES NO
Unique Numbers Riddle
Hint:
All numbers(0-9) appears in alphabetical order and once. Did you answer this riddle correctly?
YES NO
YES NO
Finding The Number Riddle
What number am I? I am a three digit number. My tens digit is five more than my ones digit. My hundreds digit is eight less than my tens digit.
Hint:
Odd Number Becomes Even
Can you solve this classic number riddle before getting hung?
Hint: Spell the number out.
150 Pens Riddle
Rihanna brought home 150 pens but while packing them, she misplaced some of them. When her brother asked how many she had misplaced, she told him:
If you count in pairs, one will remain
If you count in a group of three, two will remain
If you count in a group of four, three will remain
If you count in a group of five, four will remain
If you count in a group of six, five will remain
If you count in a group of seven, nothing will remain.
How many pens do you think has she misplaced ?
If you count in pairs, one will remain
If you count in a group of three, two will remain
If you count in a group of four, three will remain
If you count in a group of five, four will remain
If you count in a group of six, five will remain
If you count in a group of seven, nothing will remain.
How many pens do you think has she misplaced ?
Hint:
Adding To 1000 Riddle
Do this in your head don't use paper and pencil or a calculator just your mind.
Take 1000 and add 40. Now add 1000, add 30,add 1000, add 20, add 1000, add 10
what is your answer?
Take 1000 and add 40. Now add 1000, add 30,add 1000, add 20, add 1000, add 10
what is your answer?
Hint:
The Special Numbers Riddle
Hint:
It is the numbers from 1 to 9 in alphabetical order.
Eight
Five
Four
Nine
One
Seven
Six
Three
Two Did you answer this riddle correctly?
YES NO
Eight
Five
Four
Nine
One
Seven
Six
Three
Two Did you answer this riddle correctly?
YES NO
The Four Digit Number Riddle
Can you find the four digit number in which the first digit is one fourth of the last digit, the second digit is 6 times the first digit, and the third digit is the second digit plus 3?
Hint:
Match The Number Of Letters
This can be a little tricky if you misread the riddle. There's a little known fact in this once you've found the answer. Also being that the answers are limited, it's recommended to challenge yourself and begin the timer to solve this in under 30 seconds.
Spell me out and I am the number of a month in which I also match the number of letters exactly of this month. What am I?
Hint: There are only 12 months
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
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
1500 Plus 20 And 1600 Minus 40 Riddle
Hint:
Friday The 13th Dance Riddle
Hint:
Italian's Eating On Friday The 13th
Hint:
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