Unit 8 · Detecting Reasoning Errors

Lauren's School Club — Necessary Condition Error

Lesson 6 of 34

Premium

About this lesson

To join the basketball team you must be 140 cm tall. Lauren grew to 141 cm. Miriam says she'll definitely be chosen. What's the mistake? The height rule is a necessary condition — it gets you through the door, but it doesn't guarantee you'll be chosen.

Chapters

0:00Introduction
0:23Question
1:16Strategy
1:58Step 1: Understand the rule — necessary vs sufficient
2:49Step 2: Test each option — find the one that names the flaw
3:40Correct answer

Question

Lauren wants to join her school's basketball team. To qualify, players must be at least 140 centimetres tall.

Miriam: "Lauren was 139 centimetres tall last year, but she has now grown to be 141 centimetres tall. So, she will definitely be chosen to be part of the team this year."

Which one of the following sentences shows the mistake Miriam has made?

Free account · Selective

Take your Selective prep further

  • Sample questions & worked solutions across core Selective topics
  • Digital exam simulator with interactive practice sets
  • Personalised progress tracking across all your devices
Create free account

Already have an account? Log in here

No payment required. Compare Selective plans

0 of 34 lessons completed

0%

Give Your Child the Best Chance at Selective Entry

Join NSW families preparing their children for the Selective Schools Placement Test with the most realistic online Selective practice tests available. First tests free—no credit card required.

Claim Your Free Selective Practice Tests