A pitcher of water at 40 degrees Fahrenheit is placed into a 70 degree room. One hour later, the temperature has risen to 45 degrees. How long will it take for the temperature to rise to 60 degrees?

3 hours

Step-by-step explanation:

The difference between the initial temperature and the temperature after an hour is an increase of 5 degrees. Since we need to calculate the time it would take for the temperature to rise to 60 degrees we need to find the difference in degrees from the current temperature to 60 degrees.

60 - 45 = 15 degrees

Since 1 hour equals an increase of 5 degrees we need to divide 15 by 5 to calculate how many hours before the temperature increases to 60 degrees

15 / 5 = 3 hours