KA-0092Ordering and ranking from clues
4 points, difficulty 2 of 3Level 5–6about 90sFive children queue up. Ana is somewhere ahead of Bo. Cal is behind Bo but ahead of Dee. Eve is last. Who is second in the queue?
Hints
Take them one at a time. The first gives nothing away.
1A nudge
Draw one line and place them on it.
2The strategy
Each clue is a link in a chain. Write the links down as you read them, then see whether they join end to end - if they do, the whole order is fixed.
3The full solution
Ana is before Bo, Bo before Cal, Cal before Dee, and Eve is last. That chains to Ana, Bo, Cal, Dee, Eve - so Bo is second.
Solution— no shortcut on this one
Turn each clue into a link. Ana before Bo. Cal after Bo but before Dee, so Bo before Cal before Dee. Chaining: Ana, Bo, Cal, Dee. Eve is last, which is the fifth place, and the chain fills the first four exactly. So the order is fully determined and Bo is second. The transferable idea: draw one line and place people on it as the clues arrive - the moment the links chain end to end, the order is fixed.
Why this is on the test: Reading before as immediately before is the classic misreading, and it is what makes students think an order is ambiguous when it is not.