Final answer:
To express 31 minutes as a decimal part of an hour, divide 31 by 60. The result is a non-terminating decimal.
Step-by-step explanation:
To express 31 minutes as a decimal part of an hour, we divide 31 by 60, because there are 60 minutes in an hour. This gives us the decimal 0.5167. Since the decimal doesn't terminate or repeat, it is a non-terminating decimal.