Which scores in the fourth test let Riya pass…

Which scores in the fourth test let Riya pass the course?

Question 32

MediumOriginal 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 scores in the fourth test let Riya pass the course?

40 \le x \le 100

Correct answerYour answer

75 < x \le 100

Correct answerYour answer

60 \le x \le 100

Correct answerYour answer

75 \le x \le 100

Correct answerYour answer

Show the answer and explanation

CorrectNot quiteAnswer D

Correct answer: D

$165 + x \ge 240$ gives $x \ge 75$ ; she also needs $x \ge 40$ , which 75 already beats.
A test is out of 100, so $75 \le x \le 100$ .

Worth noting

$40 \le x$ meets only the per-test rule; the average needs 75.

Concept: Combining two conditions
Typical timeTypical: 120 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 scores in the fourth test let Riya pass the course?

Question 32

Explanation