Question 760863
Tank will be increased in capacity by a factor of {{{72.96/42.56=whatever it is}}}.


Initial volume, v.
{{{highlight(v+10=v*(72.96/42.56))}}}


The 10 added gallons of capacity makes a volume increase by a factor of approximately 1.71.  


{{{((72.96/42.56)-1)v=10}}}
switch to decimal approximation:
{{{(1.71428-1)v=10}}}
{{{0.714286*v=10}}}
{{{v=10/0.714286}}}
{{{highlight(v=14)}}} gallons