Question 304687
{{{(1/3)(a+b) = a-5}}}
{{{a+b = 3(a-5)}}}
{{{a+b = 3a - 15}}}
{{{b + 15 = 2a}}}

But a and b are consecutive odds numbers. So {{{a+2 = b}}}
{{{b + 15 = 2a}}}
{{{(a+2) + 15  = 2a}}}
{{{a + 17 = 2a}}}
{{{17 = a}}}
So b must be 19

Check your answer
Does (1/3)(17+19) = 17-5 ???