Question

the average of paulas two test scores must be 80 or more for her to get at least a b in the class. she got a 72 on her first test. what grades can she get on the second test to make at least a b in the class?

at least 84
at least 76
at least 88
at least 92

Explanation:

Step1: Set up the average formula

Let the score of the second - test be $x$. The average of two scores is $\frac{72 + x}{2}$.

Step2: Set up the inequality

Since the average must be 80 or more, we have the inequality $\frac{72 + x}{2}\geq80$.

Step3: Solve the inequality

Multiply both sides of the inequality by 2: $72 + x\geq160$. Then subtract 72 from both sides: $x\geq160 - 72$, so $x\geq88$.

Answer:

at least 88