Question 948260
{{{k=(a+2)/2=(b+3)/3=(c+5)/5}}}
{{{2k=a+2}}}
{{{3k=b+3}}}
{{{5k=c+5}}}
Adding those three together,
{{{2k+3k+5k=a+b+c+10}}}
{{{10k=(a+b+c)+10}}}
{{{k=(a+b+c)/10+1}}}