Tag: counting
Interview Questions
- 100 prisoners and the light bulb
- Ants on a triangle
- The birthday paradox
- 1, 2, 4, 8, 16, ... and the pattern that breaks
- How often do the clock hands overlap?
- How often are the clock hands at a right angle?
- A run of days that nets a multiple of n
- How many palindrome times on a 24-hour clock?
- Ferry eight across when the boat holds four
- Everyone shouts the number of red hats, one must be right
- Handshakes at a party
- How many squares are on a chessboard?
- Most pieces of pancake from six straight cuts
- The number of odd-handshakers is always even
- The painted cube cut into 64 cubies
- Matching socks in the dark
- Splitting a team and scoring the products
- How many zeros end 100 factorial?
- How many gifts in "The Twelve Days of Christmas"?
- Two children toggling a row of lamps
- Two guests with the same number of friends
- Two switches, unknown start, prove everyone visited
- Two teams with identical payroll
- Count the ways to make change
- Count ordered ways to reach a target
- How many ways to decode a trade-ticket code
- Count contiguous stretches with exactly k distinct symbols
- Counting grid paths around obstacles
- Adjacent swaps to group buys before sells
- Count price windows whose product stays under a cap
- Expected absolute difference of two dice
- Six rolls, all six faces
- Ants on a square, and how many collisions to expect
- Biased ants on a triangle
- Ants on a pentagon, with a twist
- How many ants make a collision almost certain?
- Ants on a triangle
- At least one ace, are both aces?
- Picking a committee with exactly two men
- Probability your d20 beats mine
- Probability your card rank beats mine
- Probability you don't lose the dice duel
- Probability your d6 beats their d4
- Probability your die beats mine
- A four-digit PIN with no repeated digit
- A number divisible by 2, 3, or 5
- Exactly one friend gets their own gift back
- How many boxes stay empty?
- A flush in a strange five-suit deck
- Does the ticket number contain a seven?
- Does the delivery route pass the coffee shop?
- No child left without a toy
- Seating three couples with no pair together
- A random pizza with exactly three toppings
- Scramble five digits, is the number even?
- Will the two friends get paired up?
- Will the two of them sit directly across?
- Will the three A's clump together?
- Three coworkers, three different birth months?
- Two cards, same rank?
- Probability two dice sum to eight
- Probability at least one die shows a six
- Probability two dice sum to a multiple of three
- Probability of rolling doubles
- Probability two dice sum to seven
- Two red marbles from a small bag