Question

The temperature was -20.5°F at 5 A.M. and rose 5 degrees per hour for the next 5 hours. Melissa says the temperature at 10 A.M. was -5.5°F. Which statement identifies Melissa’s error and the correct answer?

A. Melissa multiplied incorrectly. The correct answer is -0.5°F.
B. Melissa multiplied incorrectly. The correct answer is 9.5°F.
C. Melissa added incorrectly. The correct answer is 4.5°F.
D. Melissa added incorrectly. The correct answer is 5.5°F.

Answer 1

C. Melissa added incorrectly

Explanation:

-20.5+(5×5)

Answer 2

(C) Melissa added incorrectly. The correct answer is 4.5°F.

Explanation:

To find the temperature at 10 A.M., we need to add the temperature increase to the initial temperature.

`\textsf{Temperature at 10 A.M. } \sf = -20.5^\circ F + 5^\circ F/hour * 5 \textsf{ hours}`

`\textsf{Temperature at 10 A.M. } \sf = -20.5^\circ F + 25^\circ F`

`\textsf{Temperature at 10 A.M. } \sf = 4.5^\circ F`

Therefore, the temperature at 10 A.M. was 4.5°F.

Melissa said that the temperature at 10 A.M. was -5.5°F. This is incorrect, because the temperature rises by a total of 25°F, so it should be at least 4.5°F.

Therefore, the correct answer is (C) Melissa added incorrectly. The correct answer is 4.5°F.