Riddle #3

logicshort

Difficult pop quiz

A teacher decides to give a pop quiz one day but all of her students refuse to take the quiz thinking that the teacher will call off the quiz. She can give only one of these students a detention for skipping the quiz. All of the students know each other’s names and if a student knows he/she is getting a detention they take the quiz. How can she threaten her students with the single detention so they all take the quiz?
She tells them that she will give the student who skips the quiz whose name comes first alphabetically a detention. This student won’t skip because they know they are getting a detention if they do. The next person alphabetically will then know that they will get a detention so they won’t skip either, and so on.
79.95 %
54 votes

Similar riddles

See also best riddles or new riddles.

logicshort

Twin brother

Peter celebrated his birthday on one day, and two days later his older twin brother, Paul, celebrated his birthday. How could this be?
When the mother of the twins went into labour, she was travelling by boat. The older twin, Paul, was born first, barely on March 1st. The boat then crossed a time zone,
93.39 %
38 votes

logicmathshort

Three brothers

Dean Sam and Castiel are three brothers. Interestingly their current age is prime. What's more interesting that difference between their ages is also prime. How old are they?
Sam : 2 Dean : 5 Castiel : 7 Age diff 7 - 2 = '5' is prime 7 - 5 = '2' is prime 5 - 2 = '3' is prime
93.22 %
37 votes

logicshort

A man hijacks an aeroplane

A man hijacks an aeroplane transporting both passengers and valuable cargo. After taking the cargo, the man demands two parachutes, puts one of them on, and jumps, leaving the other behind. Why did he want two?
If the officials thought he was jumping with a hostage, they would never risk giving him a faulty parachute.
93.22 %
37 votes

logicmathshort

Maths logical problem

The digits 0-9(0,1,2,3,4,5,6,7,8,9) can be rearranged into 3628800 distinct 10 digits numbers. How many of these numbers are prime?
None. The sum of numbers from 0-9(0,1,2,3,4,5,6,7,8,9) is 45 and therefore can be divisible by 3 and 9.
93.05 %
36 votes

logicmathshort

Eight eights

Using eight eights and addition only, can you make 1000?
888 + 88 + 8 + 8 + 8 = 1000
93.05 %
36 votes

logicshort

A man was driving a truck

A man was driving a truck at 60 mph. He did not have his headlights on and the moon was not up. Yet he did not hit the woman who crossed the road. How?
He was driving the truck during daytime.
92.86 %
35 votes

logicmathshort

Three positive whole numbers

Find three positive whole numbers that have the same answer added together or when multiplied together.
1,2, & 3. 1 x 2 x 3 = 6 and 1 + 2 + 3 = 6
92.67 %
34 votes

logicmathshort

A clock

A clock chimes 5 times in 4 seconds. How many times will it chime in 10 seconds?
11 times. It chimes at zero and then once every second for 10 seconds.
92.67 %
34 votes