Question 104959
1.{{{x+(x+2)+(x+4)>10}}}
2.{{{x+(x+2)+(x+4)<20}}}
From 1, 
{{{3x+6>10}}}
{{{3x>4}}}
{{{x>4/3}}}
From 2,
{{{3x+6<20}}}
{{{3x<14}}}
{{{x<14/3}}}
Remember x must be a positive odd integer. 
Let's refine our inequalities by finding the closest even integer as limit. 
{{{x>4/3}}}
{{{x>2}}}
and
{{{x<14/3}}}
{{{x<4}}}
The only positive odd integer that satisfies both requirements is 
{{{x=3}}}
3,5,7 is the only set.
Let's verify. 
{{{10<3+5+7<20}}}
{{{10<15<20}}}
Good answer.