Question 121090
For each one, d = rxt
and the sum of their distances needs to be 21 mi
For Jim:
{{{d = 6t}}}
For Sarah:
{{{d = (1/3)t}}}
{{{6t + (1/3)t = 21}}}
multiply both sides by 3
{{{18t + t = 63}}}
{{{19t = 63}}}
{{{t = 3.316}}}hrs answer
or
{{{3}}}hrs {{{.316*60}}}min
{{{3}}}hrs {{{19}}}min
I can check this. I should get the same answer
if Jim alone went 21 miles at 6.333 mi/hr
{{{21 = 6.333*3.316}}}
{{{21 = 20.999988}}} close enough