What number does not belong 5 15 20 35 58?

Answer 1

• 5 does not belong because it's the only one that is prime, and it is also the only one that is a single digit.
• 58 does not belong because it's the only one that's not a multiple of five.
• 20 does not belong because unlike the other numbers, one of it's digits is not a five.

That's the problem with this kind of question. They expect it to have one correct answer, but there are in fact several. Chances are, the expected answer is 58. One could argue though that - having two interesting distinctions - the number five belongs even less than 58 with it's single distinction.