9514 1404 393
Answer:
4, 5, 6, maybe 2
Explanation:
You're looking for values strictly between 6 and 7. In decimal, the number will have a leading digit of 6 and a non-zero decimal fraction.
1. √36 = 6 . . . out of range
2. 2πr ≈ 6.28r . . . value depends on r (presumed not in range)*
3. 14/2 = 7 . . . out of range
4. 1/0.15 ≈ 6.666...(repeating) . . . in range
5. 25/4 = 6.25 . . . in range
6. tan(81°) ≈ 6.31... . . . in range
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* of course, 2π will be in range.