11+ Selective Thinking Skills Exam Questions & Answers 2026 (21–30)

Question 1

A park sign states: 'No dogs have ever been reported biting visitors in this park, so it is safe to let your dog off the lead here.' What must the sign be assuming?

TheoryPractice · Accepted Answer

All dog bites in the park have been reported. The sign's claim of safety is based on the absence of reported bites, which only supports the conclusion if every bite that occurred was actually reported.

Question 2

A teacher argues: 'Students who sit at the front of the classroom get higher grades. Therefore, if we move struggling students to the front, their grades will improve.' What is the necessary assumption?

TheoryPractice · Accepted Answer

Sitting at the front causes better grades, rather than higher-achieving students choosing front seats. The teacher's plan only works if sitting at the front causes higher grades; if instead motivated students choose front seats, moving students there would not improve performance.

Question 3

Fatima says: 'Every time I wear my lucky green socks, our team wins. I'm wearing them today, so we'll win.' Which assumption does Fatima's argument depend on?

TheoryPractice · Accepted Answer

The green socks have some influence on the match outcome. Fatima's prediction is only logical if she assumes the socks actually affect the result; without that assumption, past wins while wearing the socks provide no basis for predicting today's result.

Question 4

A council newsletter says: 'Noise complaints in Riverside Street dropped by 40% after the new speed bumps were installed. The speed bumps have clearly reduced noise.' What must this argument assume?

TheoryPractice · Accepted Answer

Nothing else changed in Riverside Street that could have reduced noise. Attributing the drop in complaints to the speed bumps requires assuming no other change — such as fewer residents or less traffic — could explain the reduction.

Question 5

Zara argues: 'Our drama club put on a show last year and raised £400 for charity. We should do another show this year to raise money.' What assumption is essential to her argument?

TheoryPractice · Accepted Answer

The drama club will be able to raise a meaningful amount again. Zara's recommendation to put on another show rests on the assumption that doing so will actually raise money — that last year's success can be replicated.

Question 6

Oliver reads: 'Children who own more books score higher on reading tests. Parents should therefore buy more books for their children.' What must this advice assume?

TheoryPractice · Accepted Answer

Owning more books leads to better reading, not that better readers are given more books. The advice to buy more books is only sound if book ownership causes reading improvement; if instead skilled readers simply receive more books as gifts, buying more would not help.

Question 7

Kofi argues: 'The new homework app has been used by students for one term. Test scores have risen. The app is responsible for the improvement.' Which assumption is this argument making?

TheoryPractice · Accepted Answer

No other factors changed during that term that could explain the score rise. Crediting the app for better scores requires ruling out other explanations, so the argument must assume nothing else — such as a new teacher or revised curriculum — also changed.

Question 8

A scientist states: 'In our experiment, plants given extra carbon dioxide grew 20% taller than the control group. Carbon dioxide therefore promotes plant growth.' What is the necessary assumption?

TheoryPractice · Accepted Answer

The two groups of plants were identical in all other relevant conditions. The conclusion that carbon dioxide caused the extra growth depends on assuming every other variable was held constant, so that the only difference between the groups was the carbon dioxide level.

Question 9

A campaigner argues: 'Regions with more fast-food outlets have higher rates of childhood obesity. Banning new fast-food outlets will therefore reduce childhood obesity.' What must this argument assume?

TheoryPractice · Accepted Answer

Fast-food outlets contribute to obesity rather than both being caused by a third factor. A ban on outlets can only reduce obesity if the outlets are actually causing it; if both obesity rates and outlet numbers are driven by a common factor such as poverty, the ban would not help.

Question 10

Nia says: 'My older brother revised for six hours a day and got top marks. If I revise for six hours a day, I will also get top marks.' Which assumption is strictly necessary?

TheoryPractice · Accepted Answer

Six hours of revision per day is sufficient for Nia to achieve top marks. Nia's conclusion only follows if she assumes that the same revision hours will be sufficient for her — without this, her brother's experience offers no guarantee about her own outcome.

11+ Selective Thinking Skills Exam Questions & Answers 2026 (21–30)

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