Critical thinking: Practice 1

10 original teaching questions with answers and explanations.

Instructions for this set

Select the best-supported conclusion or evaluation for the precise question. These teaching items use four options, not official Watson-Glaser response scales.

Feedback mode has no time limit or negative marking. The optional timed challenge allows 15 minutes and uses the scoring shown on its rules screen. Those settings are not official assessment rules.

Practise with feedback Optional timed challenge

  1. 1. A cafe proposes mobile ordering to reduce its counter queue. Which assumption is necessary for that proposal to reduce the queue through mobile ordering?
    1. Enough customers will use mobile ordering instead of ordering at the counter
    2. Every customer has a new phone
    3. The cafe will double its prices
    4. All staff prefer mobile apps

    Reference: q-b095775a-154 · Report this question

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    Answer: A. Enough customers will use mobile ordering instead of ordering at the counter

    The proposed mechanism needs some counter orders to shift to mobile. It does not require universal adoption or a particular phone model.
  2. 2. A survey of 30 volunteers from a cycling club finds 90% cycle to work. What is the strongest objection to using this as the city commuting rate?
    1. Thirty is an odd number
    2. Cycling-club volunteers may not represent city commuters
    3. Percentages cannot describe transport
    4. Volunteers always lie

    Reference: q-fdcd9c1b-145 · Report this question

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    Answer: B. Cycling-club volunteers may not represent city commuters

    The sample is selected from a group particularly likely to cycle, so it can be biased even if every response is accurate.
  3. 3. Staff who took an optional course had a lower recorded error rate than staff who did not. What cannot yet be concluded?
    1. The groups had different error rates
    2. The course caused the lower error rate
    3. A course was offered
    4. Some staff took the course

    Reference: q-6f67fa2a-120 · Report this question

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    Answer: B. The course caused the lower error rate

    The recorded rates differ, but prior ability, motivation or experience could explain that difference. Observed association alone does not establish that the course caused it.
  4. 4. A project saved $12,000 but cost $15,000 to run over the same period. Ignoring all other effects, what follows?
    1. It generated a $3,000 net saving
    2. It had a $3,000 net cost
    3. Its saving exceeded its cost
    4. Its net effect cannot be calculated

    Reference: q-8ebf55be-112 · Report this question

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    Answer: B. It had a $3,000 net cost

    The net financial result is 12,000 minus 15,000 = minus $3,000.
  5. 5. Should a council extend library hours? Which argument is most directly relevant?
    1. A pilot found substantial use during the extra hours at a stated affordable staffing cost
    2. The library building has blue doors
    3. Some unrelated parks close early
    4. The proposal has a memorable name

    Reference: q-79cecdf8-81 · Report this question

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    Answer: A. A pilot found substantial use during the extra hours at a stated affordable staffing cost

    Use and cost of the proposed extension directly address the decision. The other reasons do not establish its merits.
  6. 6. Each product has one final inspection result: pass or fail. Only products with a final pass may be released. Product T has a final fail. Which conclusion follows under the stated rule?
    1. T may be released
    2. T may not be released
    3. T was the only failure
    4. Every inspected product may be released

    Reference: q-523c3818-185 · Report this question

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    Answer: B. T may not be released

    Permission to release requires a final pass. T has a final fail, so T may not be released under the rule. The final-result wording excludes an unstated later retest.
  7. 7. A report says complaints fell from 20 to 10 while orders fell from 1,000 to 200. What happened to the complaint rate per order?
    1. It fell from 2% to 1%
    2. It rose from 2% to 5%
    3. It stayed at 2%
    4. It rose from 5% to 10%

    Reference: q-3c6a4b4-128 · Report this question

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    Answer: B. It rose from 2% to 5%

    Initial rate = 20/1,000 = 2%. Later rate = 10/200 = 5%. Counts and rates tell different stories.
  8. 8. A manager says, "We must keep the old software because we have already spent $50,000 on it." Which missing comparison matters most?
    1. Past spending versus the colour of its logo
    2. Future costs and benefits of keeping it versus replacing it
    3. Whether $50,000 is an even number
    4. How long the software name is

    Reference: q-62005bfb-132 · Report this question

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    Answer: B. Future costs and benefits of keeping it versus replacing it

    The amount already spent does not by itself settle the decision. Compare future costs and benefits, including any recoverable resale value, of keeping the software versus replacing it.
  9. 9. A product has 4.8 stars from five reviews; another has 4.6 from 2,000 reviews. Which claim is best supported by these figures alone?
    1. The first is certainly better for every buyer
    2. The second has more reviews but a lower displayed average
    3. The first has fewer defects
    4. The second reviews are all genuine

    Reference: q-c256404-133 · Report this question

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    Answer: B. The second has more reviews but a lower displayed average

    The supplied figures establish count and average only. They do not establish product suitability, defect rates or review authenticity.
  10. 10. A policy says an exception is allowed only with written approval. An exception was allowed in full compliance with that policy. What must be true?
    1. Written approval existed
    2. Every request was approved
    3. The approval was verbal only
    4. No approval was needed

    Reference: q-e103dbe0-147 · Report this question

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    Answer: A. Written approval existed

    The exception requires written approval. Compliance therefore entails that approval existed.

Review your method

Return to the critical thinking lesson and identify the reasoning step behind each mistake before repeating the set.

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