Riddle: If you have two hourglasses -- one four-minute timer and one seven-minute timer, how can you measure nine minutes?
Answer: Turn over both hourglasses at once.
When the four-minute hourglass runs out, turn it over.
When the seven-minute hourglass runs out, turn it over.
When the four-minute timer runs out this time (eight minutes have elapsed), the seven-minute hourglass has been running for one minute.
Now turn over the seven minute timer back over. When the timer runs out, nine minutes have elapsed.
When the four-minute hourglass runs out, turn it over.
When the seven-minute hourglass runs out, turn it over.
When the four-minute timer runs out this time (eight minutes have elapsed), the seven-minute hourglass has been running for one minute.
Now turn over the seven minute timer back over. When the timer runs out, nine minutes have elapsed.
April Fools Day Riddles are hand picked April Fools Day Riddles for use by teachers in the classroom and for home school lessons. This april fools day riddles quiz provides the option to be downloaded as a PDF or printable directly from the April Fools Day Riddles quiz page.
St Patricks Day Riddles are hand picked St Patricks Day Riddles for use by teachers in the classroom and for home school lessons. This st patricks day riddles quiz provides the option to be downloaded as a PDF or printable directly from the St Patricks Day Riddles quiz page.
Mothers Day Riddles are hand picked Mothers Day Riddles for use by teachers in the classroom and for home school lessons. This mothers day riddles quiz provides the option to be downloaded as a PDF or printable directly from the Mothers Day Riddles quiz page.
