Question 38339
Letting x be the speed:
EQUATION:
{{{36/(x-3)-36/(x+3)=1}}}
36[(x+3)-(x-3)]=(x+3)(x-3)
{{{36(6)=x^2-9}}}
{{{216=x^2-9}}}
{{{x^2=225}}}
x=15
Hence, the speed of the boat is 15mph.
Paul.