Question 46443
Julio's time = x-10
Dan's time = x
EQUATION:
{{{1/x+1/(x-10)=1/12}}}
{{{x-10+x=((x)(x-10))/12}}}
{{{2x-10=(x^2-10x)/12}}}
{{{24x-120=x^2-10x}}}
{{{x^2-34x+120=0}}}
Factor:
x=4 and x=30
reject x=4
30-10=20
Hence, one person can do a job in 30 minutes and another person can do the same job is 20 minutes.
Paul.