Question 440961
Let {{{s}}} = his average speed for the return trip.
given:
To town hall:
(1) {{{ d = (s + 9)*1.8 }}}
The trip back:
(2) {{{ d =  s*2.2 }}}
Set (1) equal to (2)
{{{ (s + 9)*1.8 = 2.2s }}}
{{{ 1.8s + 16.2 = 2.2s }}}
{{{ .4s = 16.2 }}}
Trip back:
{{{ s = 40.5 }}}
To town hall:
{{{ s + 9 = 49.5 }}}