### Playing With Numbers

goals
If $n$ represents an odd integer, which of the following must be even integers?
$2n,3n,3n+1,3n-5,4n+1$
How many multiples of $3$ are between $23$ and $82$?
The largest integer that divides product of any four consecutive integers is
If $k$ represents an integer, which of the following must be even integers?
$2k,2k+6,\cfrac { 8k }{ 4 } ,3k+5,2k-1$
$\cfrac{2}{15}+\cfrac{2}{3}=$