Real Numbers — O/L Mathematics

How do I practise Real Numbers?

1 question with a worked solution

1. Which of the following numbers is an irrational number?
   1. A) 22/7
   2. B) √7
   3. C) √16
   4. D) 0.375
   Check my answer

   Correct answer: B) √7

   √7 cannot be expressed as a fraction a/b where a and b are integers; its decimal expansion is non-terminating and non-recurring. 0.375 = 3/8 (rational), √16 = 4 (rational), and 22/7 is a ratio of integers (rational).

   Show worked solution

   Step 1: Definition of irrational number: a real number that cannot be written in the form p/q (p, q ∈ ℤ, q ≠ 0). Step 2: 7 is a prime number, so its square root √7 is irrational. Step 3: Check others: 0.375 = 375/1000 = 3/8 (rational), √16 = 4 = 4/1 (rational), 22/7 (rational fraction). Answer: √7.
   Modelled on: the O/L Mathematics examination pattern

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Where does Real Numbers fit in the syllabus?

Grade 11 · Term 1