Chapter 5.4, Problem 49PFA

To determine

Find which compound inequality represents the temperature t when the glue will work.

Answer to Problem 49PFA

Option $\text{A:}45<t<78$ is correct.

Explanation of Solution

Given:

A certain type of glue will not work if the temperature is less than 45⁰F or if the temperature 78⁰F or above.

4 options are here:

  $\begin{array}{l}\text{A:}45<t<78\\ \text{B:}45\le t<78\\ \text{C:}45<t\le 78\\ \text{D:}45\le t\le 78\end{array}$

Concept Used:

A certain type of glue will not work if the temperature is less than 45⁰F or if the temperature 78⁰F or above.

The compound inequality will not work: $t<45ort\ge 78$

So, the compound inequality of temperature t when the when the glue will work is $45<t<78$

Option $\text{A:}45<t<78$ is correct.

Thus, option $\text{A:}45<t<78$ is correct.