Question

In order to keep a specific bacteria alive, the tempature in a science lab, cannot exceed -20F. The electricity went out, when the tempature was -72F, but is increasing at a rate of 6.5 per hour. How many hours do the scientist have until the bacteria is not safe?

Answer 1

Answer:

At most 8 hours

Step-by-step explanation:

Given

$Maximum = -20F$

$Rate = 6.5/hour$

$Base\ Temperature =-72F$

Required

Determine the time taken

Represent time by t.

The relationship between all parameters is:

$Maximum = Base\ Temperature + Rate * t$

$Base\ Temperature + Rate * t \leq Maximum$

This is so (≤) because, according to the question, the temperature can not exceed the maximum.

So, we have:

$-72 + 6.5*t \leq -20$

$-72 + 6.5t \leq -20$

Collect Like Terms

$6.5t \leq -20 + 72$

$6.5t \leq 52$

Solve for t

$t \leq 52/6.5$

$t \leq 8$

Hence, they have at most 8 hours