Question

The sum of 3 consecutive odd integers is between 21 and 39. Which of the following inequalitites expresses the relationship if n represents the smallest integer?
21<3n+4<39
21<6n<39
21<3n+3<39
21<3n+6<39
Please show me how to do this.

Answer 1

n is the smallest number
n+2 is the next consecutive odd integer
n+4 is the 3rd consecutive odd integer
We know that n+ (n+2) + (n+4) < 39 and that n + (n+2) + (n+4) >21 because that is given.
so, 21<3n+6<39

Answer 2

Thank You