Could be true is not must be true

Build the list. The options come last.

Most of this question type is the order you work in.

First, find the facts that fix somebody — a score, a time, a position. Those are free information and they should be written down before anything else.

Then use the facts that only fix an order — who is above whom. Write it as a list, initials only.

And only now look at A to E. Reading the options first means reading five plausible sentences before you know anything, and every one of them will sound reasonable.

Could be true is not must be true

This is the idea the whole question type is built around.

If the question asks what must be true, then a sentence that merely could be true is a wrong answer. It has to be true in every single way the gaps could be filled in.

So don't ask yourself whether it sounds right. Ask: can I break it?

Try to invent a filling-in that makes it false. If you can, it is out. If you honestly cannot, that is your answer.

The sentence nobody mentioned

Here is something usable straight away. Nearly every set has an option about something the facts do not mention at all — who trains on a Tuesday, who has played before, what colour something is.

You cannot prove it. You also cannot disprove it. So it can never be the sentence that must be true, and it can never be the sentence that cannot be true.

Scan for it first and cross it out. That is one option gone in about two seconds, before any thinking has happened.

The three-second check that saves the mark

Before marking anything, read the last line of the question again.

Cannot be true, or must be true?

The papers put those two next to each other on purpose. A child who works out the answer to the other one has done every bit of the thinking and thrown the mark away.

Where do pupils lose marks?

Choosing a statement that could be true, because it sounds sensible.

Reading the options before building the list, so five plausible sentences arrive before any structure does.

Answering must when the question said cannot, or the other way round.

Trying to hold the orders in their head instead of writing them out. Three lines of initials is all it takes.

Try it yourself

Build the list before you read the options. Then, for each one, try to break it.

1. Five children finished a race. Amara finished before Callum. Devi finished last. Priya finished immediately after Amara. Callum did not finish first. Write down every possible finishing order.
2. Which of these must be true? A: Rowan finished first. B: Priya finished before Callum. C: Amara finished second. D: Callum finished fourth.
3. Which of these cannot be true? A: Amara finished first. B: Devi finished before Priya. C: Rowan finished third.
4. Why is 'Rowan finished first' a wrong answer to the must-be-true question?
5. A fifth option says 'Rowan has run this race before.' What do you do with it?

Show Answers

How much practice does this type need at home?

The valuable habit is writing out every possible arrangement, because children resist it — it feels like more work than thinking, and it is less. Once three lines of initials are on the page, the options answer themselves.

The other thing worth drilling is the flip: give the same facts and ask alternately what must be true and what cannot be true, so the difference between the two questions stops being invisible.