A nurse is instructed to check a patient's blood pressure every 40 minutes, and another is instructed to take the same patient's temperature every 60 minutes. If both nurses are in the patient's room now, how long will it be until the nurses are together in the room once again?

a. 80 minutes
b. 120 minutes
c. 160 minutes
d. 200 minutes

To determine when two nurses will be together in the patient's room again, we need to find the least common multiple (LCM) of their visit intervals, which are 40 and 60 minutes. The LCM of 40 and 60 is 120 minutes, so the nurses will be together in the room again after 120 minutes.

Explanation:

The question relates to finding a common multiple of two different intervals. A nurse checks a patient's blood pressure every 40 minutes while another takes the patient's temperature every 60 minutes. To determine when the nurses will be together in the room again, we need to find the least common multiple (LCM) of 40 and 60.

Here are the multiples of 40: 40, 80, 120, 160, 200, ...

And here are the multiples of 60: 60, 120, 180, 240, ...

The smallest multiple that appears in both lists is 120 minutes.

Thus, it will be 120 minutes before both nurses are together in the room once again.

The correct answer is b. 120 minutes.