Set Intersection ↗
Find the element shared by two sets.
Solve a small age relationship using simple algebra.
Enable JavaScript to play. Instructions remain available below.
How old is Sam now? Lee is 20. Lee is 8 years older than Sam.
the answer is 12. Subtract the age difference from the older age.
Write down what is known and what is only assumed. Look for constraints that eliminate possibilities, then test a small next step. A wrong answer is useful information about the strategy you chose.
This is a recreational logic activity. Results describe performance on this particular task, with this device and these rules. They are not a clinical assessment, IQ score or promise of improvements in daily life. Your best result and recent sessions stay in this browser; no account is required.
Yes. You can play the full activity without a payment, download or account.
Use Tab to focus buttons and Enter or Space to activate them. Answer fields accept normal typing. The maze also supports arrow keys. Timed tests will differ between touch, mouse and keyboard input.
Practice, a different generated puzzle, distractions and input timing all affect results. Compare several sessions rather than drawing a conclusion from one attempt.