Question 943042
Interesting how you asked this same question again but with slightly different given values.  We can generalize the analysis and solution.



ASSIGN VARIABLES
U, the speed for going to.
V, the speed for returning.
T, total time going and returning.
d, the one-way distance, unknown.


___________________rate_________time_________distance
GOING______________U____________(___)__________d
RETRNG_____________V____________(___)_________d
Total____________________________T


Fill-in the missing time cells.
___________________rate_________time_________distance
GOING______________U____________d/U__________d
RETRNG_____________V____________d/V_________d
Total____________________________T



Obvious equation is {{{d/U+d/V=T}}}, with only ONE unknown variable, being d.
{{{d(1/U+1/V)=T}}}
{{{d(V+U)/(UV)=T}}}
{{{d=((UV)/(V+U))T}}}
{{{highlight(d=(UVT)/(V+U))}}}