Question 640946
Let {{{ p }}} = the selling price of the 2/5
given:
{{{ p = (2/5)*96000 - .06*(2/5)*96000 }}}
{{{ p = (2/5)*96000*( 1 - .06 ) }}}
{{{ p =  38400*.94 }}}
{{{ p = 36096 }}}
--------------
Let {{{ g }}} = the percentage gain to sell the remaining 3/5 of the land
{{{ 36096 + ( 1 + g )*( (3/5)*96000 ) = 1.1*96000 }}}
{{{ 36096 + ( 1 + g )*57600 = 105600 }}}
{{{ ( 1 + g )*57600 = 105600 - 36096 }}}
{{{ 57600g = 69504 - 57600 }}}
{{{ 57600g = 11904 }}}
{{{ g = 11904 / 57600 }}}
{{{ g = .2067 }}}
He must sell the remaining part at 20.67 % gain to 
make 10% on the whole
check:
{{{ 36096 + 1.2067*57600 = 1.1*96000 }}}
{{{ 36096 + 69505.92 = 105600 }}}
{{{ 105601.92 = 105600 }}}
OK -error due to rounding off, I think