Medium difficulty brain teasers and puzzles
Out of all whole numbers between one and five thousand, there is only one number that has a unique number of letters when you spell it out. What number is it?
Include spaces and dashes. For example, “twenty-four” and “two hundred” both have 11 letters.
View SolutionA mother randomly selected two of her children to pick up a package from the post office. There was a 50% chance both children were daughters. How many daughters does this mother most likely have?
Continue reading “How Many Daughters”What common word or phrase is this rebus referring to?
SIXTEEN
THOUSAND
FIFTY
NINE
TRILLION
THIRTYSafety in numbers
(“Safety” is spelled out downwards in the numbers listed.)
What hidden word can be found among these pairs of words?
You and a friend play “first to 100”, a game in which you start with 0, and you each take turns adding an integer between 1 and 10 to the sum. Whoever makes the sum reach 100 is the winner.
Is there a winning strategy? If so, what is it?
Continue reading “First to 100”In this maze, you must alternate going through blue and red doors – in other words, you cannot go through two blue doors in a row or two red doors in a row.
Entering through the blue door in the top left, can you find your way through the maze and exit through the red door in the top right?
What common word or phrase is this rebus referring to?
serGeant
geNeral
ensIgn
priVate
colOnel
adMiralMoving up the ranks
(Each line is a rank in the military, and “moving” is spelled upwards among the ranks.)
You have six guesses to figure out a 3 digit code. After each guess, you will be told exactly how many digits are correct but in the wrong place and how many digits are correct and in the right place. You have made these five guesses already:
What is the correct 3 digit code?
View SolutionIn a best of 3 tennis match, the player that first wins 2 sets wins the match. For a 3-set tennis match, would you bet on it finishing in 2 or 3 sets?
This question was asked in an actual D. E. Shaw quant trading interview.
Preparing for a brain teaser interview? Check out our ultimate guide to brain teaser interviews.
Continue reading “Tennis in 2 or 3 sets”Jake has a 4-digit number in mind and asks Raj to guess the number. Raj can have 7 guesses, and Jake will give him some hints after 6 guesses.
Raj makes these 6 guesses:
These were all wrong, but Jake says every guess had exactly one (and only one) correct digit in the correct position. Additionally, all the digits are different.
What should Raj’s 7th guess be?
View Solution