You have two hourglasses: one measures seven minutes and the other four minutes. How can you measure exactly nine minutes using only these hourglasses?

A closeup of a thoughtful senior man holding an hourglass | Source: Pexels
Riddle #7
Three friends shared a pizza. The first friend ate half, the second ate a third, and the third ate a sixth. How much pizza is left?
Riddle #8
Sarah, Jake, and Emma are siblings. Sarah is twice as old as Jake, and Jake is three years older than Emma. If Sarah is twelve years old, how old is Emma?
Riddle #9
You have a five-gallon jug and a three-gallon jug. How can you measure exactly four gallons of water using only these two jugs?

A closeup of a person holding a jug of water | Source: Pexels
Riddle #10
Consider a three-digit number where the second digit is four times the third digit, and the first digit is three less than the second digit. What is the number?
Riddle #11
I am the start of everything and the end of everywhere. I’m the beginning of eternity and the end of time and space. What am I?
Riddle #12
Two people were born on the same day, in the same month, and the same year. However, they are not twins. How is this possible?
