how can a chef use a 13-minute hourglass and a 5-minute hourglass to time vegetables that must steam for 21 minutes
To time the vegetables that must steam for 21 minutes using a 13-minute hourglass and a 5-minute hourglass, the chef can follow the steps below:
1. Start both the 13-minute and 5-minute hourglass simultaneously.
2. Once the 5-minute hourglass is empty, flip it again immediately.
3. Allow the 13-minute hourglass to run until it finishes and empties completely.
4. At this point, the 5-minute hourglass will have been running for 8 minutes (13 minutes - 5 minutes).
5. Flip the 5-minute hourglass as soon as the 13-minute hourglass is empty.
6. Allow the 5-minute hourglass to run until it empties completely.
7. Now, the total time that has passed since starting both hourglasses is 13 minutes + 8 minutes = 21 minutes.
8. As the vegetables had to steam for exactly 21 minutes, the chef can now remove them from the heat.
By combining the time measurements of the two hourglasses and taking advantage of the extra time provided by the 5-minute hourglass, the chef can accurately time the vegetables to steam for 21 minutes.
To time the vegetables that must steam for 21 minutes using a 13-minute hourglass and a 5-minute hourglass, the chef can follow these steps:
1. Start both the 13-minute hourglass and the 5-minute hourglass together.
2. Let the 5-minute hourglass run until it finishes, which will take 5 minutes.
3. While the 5-minute hourglass is running, the chef should keep an eye on the 13-minute hourglass.
4. Once the 5-minute hourglass is empty, flip it again to start the countdown for another 5 minutes. This flipping process takes negligible time.
5. At the same time, the chef should have noticed that the 13-minute hourglass still has 8 minutes left.
6. Now, let the 13-minute hourglass continue running until it finishes, which will take an additional 8 minutes.
7. During this time, the 5-minute hourglass should finish its second cycle, reaching a total of 10 minutes on the timer.
8. At this point, the chef will have timed a total of 13 minutes (5 minutes from the first round and 8 minutes from the second round) using the 13-minute hourglass.
9. Flip the 5-minute hourglass again to restart the countdown for another 5 minutes.
10. Now, pay attention to the 13-minute hourglass. Once it finishes for the second time, the vegetables have been steamed for a total of 16 minutes (13 minutes from the first round and 3 minutes from the second round).
11. Since the 5-minute hourglass still has 2 minutes left (reached in step 9), let it run for 2 more minutes.
12. Finally, when the 5-minute hourglass empties for the third time, the vegetables will have been steamed for a total of 21 minutes (16 minutes from the 13-minute hourglass and 5 minutes from the 5-minute hourglass).
By following this process, the chef can accurately time the vegetables to steam for 21 minutes using a 13-minute hourglass and a 5-minute hourglass.