Which inequality gives Riya's fourth score x…

Which inequality gives Riya's fourth score x that keeps her average at 60 or more?

Question 25

EasyOriginal question

To pass a course a student needs an average of at least 60 over four tests, and at least 40 in each test. Riya has scored 62, 48 and 55 in the first three tests; each test is out of 100.

Which inequality gives Riya's fourth score $x$ that keeps her average at 60 or more?

165 + x > 240

Correct answerYour answer

165 + x \ge 240

Correct answerYour answer

\frac{165 + x}{3} \ge 60

Correct answerYour answer

165 + x \le 240

Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer B

Correct answer: B

Her three scores total $62 + 48 + 55 = 165$ .
$\frac{165 + x}{4} \ge 60 \Rightarrow 165 + x \ge 240$ .

Worth noting

Dividing by 3 averages over the first three tests only; the average is over four.

Concept: Setting up an inequality from a condition
Typical timeTypical: 90 s
Your timeYours: —

The rule this testsComparing numbers

Practise this chapter →

Ten questions from Numerical Inequalities, at your own pace.

Practise this chapter →

Ten questions from Numerical Inequalities, at your own pace.

Which inequality gives Riya's fourth score x that keeps her average at 60 or more?

Question 25

Explanation