Question

Which values from the set {1,2,3,4,5} make the inequality true n + 2< 6

Answer 1

Solve the inequality first. 
n+2<6
Subtract 2 from each side
n<4
The numbers in the set that are less than 4 are:
1, 2, and 3
Hope this helps.

Answer 2

1+2=3 (3 < 6) true.
2+2=4 (4 < 6) true.
3+2=5 (5 < 6) true.
4+2=6 (6 < 6) false. (it has to be less than 6, not equal to)
5+2=7 (6 < 7) false.

the answers are 1, 2 and 3.