Question

At 3 p.m. the temperature outside was 5 1/5 degrees Fahrenheit. The temperature then fell steadily by 2 1/2 degree per hour for the next 4 hours. What was the temperature at 7 p.m.

Answer 1

Answer:

$-4.8$ degrees Fahrenheit

Step-by-step explanation:

Let $t$ be temperature.

$t$ at 3:00PM: $5.2$ degrees.

Every hour, the temperature falls by $2.5$ degrees per hour for the next four hours. Let's multiply 2.5 by 4 to find out the total temperature drop in four hours.

$(2.5)(4)=10$

In four hours, the temperature dropped 10 degrees. Since it is getting colder, let's subtract this from the original 5.5 degrees to get the temperature at 7:00PM.

$5.2-10=-4.8$

The temperature at 7:00PM was -4.8 degrees Fahrenheit.

Answer 2

2 1/2 x 4 = 10
5 1/5 - 10 = - 4 4/5
The temperature at 7 p.m. was -4 4/5 degrees Fahrenheit.