Question

A room cannot exceed the temperature of -20 degrees Fahrenheit, right now it is -72 degrees Fahrenheit. The temperature then starts to rise 6.3 degrees every hour. How many hours are there until the room temperature is surpassed?​

Answer 1

Answer:

We have 8.25 hours until the room temperature is surpassed.

Step-by-step explanation:

The initial temperature of the room is -72 F, and it rises 6.3 F every hour, which means after nth hour, the room temperature $T$ will be:

$T = -72+6.4 n$.

Therefore, the room temperature is surpassed when

$-72+6.3n> -20$

we solve for $n:$

$6.3n> -20+72$

$6.3n> 52$

$\boxed{n> 8.25\:hr}$

Thus, we have 8.25 hours until the room temperature is surpassed.