Which one of these numbers are not like the others?
21, 15, 6, 16, 27

The one that isn't the same is 16 because it's not divisible by three and all the others numbers are

The question is kind of confusing. if it's asking how many variations of answers can you give. then do 4^5 for your answer.this would be something like the first question could be a and the 2nd c or first b next c etc. if you can, ask the teacher for a better confirmation of what it's asking. if i'm assuming correctly what it's asking, it's 625 different variations.