Question 972461
Let {{{ t }}} = time in hrs going
{{{ t + 1 }}} = time in hrs returning
{{{ d }}} = one-way distance traveled
------------------------------
Going:
(1) {{{ d = 50t }}}
Returning:
(2) {{{ d = 40*( t + 1 ) }}}|
-----------------------
Substitute (1) into (2)
(2) {{{ 50t = 40t + 40 }}}
(2) {{{ 10t = 40 }}}
(2) {{{ t = 4 }}} 
--------------
(1) {{{ d = 50*4 }}}
(1) {{{ d = 200 }}}
and
(2) {{{ d = 40*( 4 + 1 ) }}}
(2) {{{ d = 40*5 }}}
(2) {{{ d = 200 }}}
--------------------
The person traveled 
{{{ 2d = 2*200 }}}
{{{ 2d = 400 }}}
400 mi total