TED-Ed: Can you solve the locker riddle? - Lisa Winer

The video tutorial presents a riddle left by an eccentric uncle in his will. The challenge involves 100 lockers, each assigned to a relative. The task is to determine which lockers remain open after a sequence of opening and closing actions based on the number of factors each locker number has. The solution reveals that only lockers with an odd number of factors, which are perfect squares, remain open. The code to the safe is derived from the first five prime-numbered lockers, allowing the protagonist to claim the inheritance.

What was the main reason your uncle created a puzzle for the inheritance?

• To make the inheritance process fun

• To ensure the money is shared equally

• To test your knowledge of riddles

• To prevent relatives from pestering you

What action does Heir 2 take in the locker puzzle?

• Closes every second locker

• Opens every locker

• Opens every locker with an odd number

• Changes the status of every third locker

How is the number of times a locker is touched determined?

• By the number of heirs

• By the number of factors of the locker number

• By the number of words inside the locker

• By the position of the locker

Which lockers remain open at the end of the puzzle?

• Lockers with an odd number of factors

• Lockers with a single word

• Lockers with prime numbers

• Lockers with even numbers

What is the code to the safe?

• 2-3-5-7-11

• 10-20-30-40-50

• 5-10-15-20-25

• 1-2-3-4-5