Two hourglasses

Two hourglasses

 Riddle: If you have two hourglasses — one four-minute timer and one seven-minute timer, how can you measure nine minutes?

Here is the 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.

Comment!