Answer: it will take 5 hours to reach -1 °F.
Step-by-step explanation:
The temperature changes -4 degrees Fahrenheit per hour. This is a linear rate. The rate at which the temperature is decreasing is in arithmetic progression. The formula for determining the nth term of an arithmetic sequence is expressed as
Tn = a + (n - 1)d
Where
a represents the first term of the sequence(the starting point)
d represents the common difference.
n = x = the number of terms in the sequence(number of hours)
From the information given,
a = 0(at 1 pm, number of hours is 0)
d = - 4 degrees (it is decreasing)
Tn = -1 °F.
We want to determine the number of hours, x when Tn = -1 °F
Therefore,
- 1 = 0 + (x - 1)- 4
- 1 = - x + 4
x = 4 + 1
x = 5 hours
