Question

At 7:00 a.m., the temperature was 20°F. Over the next four hours, the temperature
dropped 20°F. Which of these statements are true? Select three that apply.
A. The temperature was 45°F at 11:00 a.m. because adding 25 and 20 gives 45.
B. The temperature was 0°F at 11:00 a.m., calculated as 20 – 20 or 20 + (–20).
C. The change in temperature is represented by –20, indicating a decrease of 20
degrees.
D. The change in temperature is represented by +20, which incorrectly shows the
magnitude but not the direction of change.
E. The expression 20+(–20) represents the temperature at 11:00 a.m.
F. The expression 25+20 represents the temperature at 11:00 a.m., failing to account for
the temperature drop.

Answer 1

Let's analyze the situation:

- At 7:00 a.m., the temperature is 20°F.
- There is a drop of 20°F over the next four hours.

Now let's calculate the temperature at 11:00 a.m.:

Initial temperature = 20°F
Temperature drop = 20°F
Temperature at 11:00 a.m. = 20°F - 20°F = 0°F

Now let's evaluate each statement:

A. **False**. The temperature was 0°F at 11:00 a.m., not 45°F. The calculation 25 + 20 does not apply here.

B. **True**. The temperature was indeed 0°F at 11:00 a.m., calculated as 20 - 20 or 20 + (-20).

C. **True**. The change in temperature being represented as -20 does indicate a decrease of 20 degrees.

D. **False**. The change in temperature is correctly represented by -20, not +20.

E. **True**. The expression 20 + (-20) indeed represents the temperature at 11:00 a.m., yielding 0°F.

F. **False**. The expression 25 + 20 does not correctly account for the temperature drop and thus is not valid.

Based on the analysis, the true statements are:

- B. The temperature was 0°F at 11:00 a.m., calculated as 20 – 20 or 20 + (–20).
- C. The change in temperature is represented by –20, indicating a decrease of 20 degrees.
- E. The expression 20+(–20) represents the temperature at 11:00 a.m.