Certificates / Logical reasoning / Classification (Odd one out)
Classification (Odd one out): lesson, then the certificate test
Step 1: the lesson (about 1 min)
Three items share one property; the fourth does not.
- Check categories first (fruits, tools, rivers), then number properties (prime, square, even), then letter positions.
- If more than one item looks odd, pick the property that the other three share most clearly.
Worked example
Which is the odd one out: 49, 64, 81, 98?
- 49 = 7², 64 = 8², 81 = 9²
- 98 is not a perfect square
Answer: 98
Watch out
- Stopping at the first difference you see: check that the other three really share a property.
Made by Shishya (AI-assisted): a general method in our own words, with our own example; no exam or platform question is copied.
Step 2: the test
- 15 questions from Shishya's checked question bank, 20 minutes. Pass mark: 11 correct.
- Scored on Shishya's server; the answers are not shown afterwards, so the test stays fair. Each attempt draws new questions.
- Free. Your first test needs no account; sign up free to take more. Your answers and score are not stored; if you pass, you choose the name to print (ages 13 and up).
- It is a Shishya completion certificate — not a university or government credential. The test is not supervised.