Question 570853
average speed = ( distance traveled ) / ( time to travel the distance )
given:
{{{ t[1] = 2/8 }}} 
{{{ t[1] = 1/4 }}} hr
and
{{{ t[2] = 2/6 }}} 
{{{ t[2] = 1/3 }}} hr
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Ave speed = {{{ ( 2 + 2 ) / ( 1/4 + 1/3 ) }}}
{{{ 4 / ( 3/12 + 4/12 ) }}}
{{{ 4 / (7/12) }}}
{{{ 4*(12/7) }}}
{{{ 48/7 }}}
{{{ 6.857 }}} km/hr