Question 1139947
{{{ 370000 - 70000 = 300000 }}}
{{{ A = A[0]*( 1 + r/n )^(n*t) }}}
{{{ A = 300000*( 1 + .063/12 )^(12*25) }}}
{{{ A = 300000*( 1 + .00525 )^300 }}}
{{{ A = 300000*4.81088 }}}
{{{ A = 1443264.03 }}}
{{{ I = A[0] - A }}}
{{{ I = 1443264.03 - 300000 }}}
{{{ I = 1143264.03 }}}
He pays $1,143,264.03 in interest
He pays $1,443,264.03 total
Get a 2nd opinion if needed and 
check my math