Question

mississippi live streaming weather radio broadcast from NOAA weather stations gives local weather updates every 18 minutes. The first update is at 2:00pm. you turn on the radio on at 5:30pm. How long will you have to wait for the next weather update?

Answer 1

Since they give updates every 18 minutes, thus any time being a multiple of 18 after 2 pm will be the time they give update.

5:30 pm is 3 hours 30 minutes for 2 pm or 150 minutes from 2 pm.

In 150 minutes, there are eight 18 minutes that have passed and is remaining 6 minutes for the next multiple of 18.

Therefore, you have to wait for 6 minutes for the next weather update.

Answer 2

Note that 5:30pm is 3 hours and 30 minutes from 2:00pm. And 3 hours 30 minutes is equivalent to 3*60 + 30 = 210 minutes. Since the local weather updates every 18 minutes, we have to wait for multiples of 18 minutes for the next weather update. We can see that 18 goes into 210 eleven times with a remainder of 12. So we're 12 minutes pass the latest weather update at 5:00pm, meaning that we have to wait 6 minutes more for the next weather update.

Thus the answer is 6 minutes.