Question 947568
The shortest distance 
she could have walked is
{{{ d[1] = 3*5 }}}
{{{ d[1] = 15 }}} km
The longest distance
she could have walked is
{{{ d[2] = 4*5 }}}
{{{ d[2] = 20 }}} km
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{{{ 19 }}} km is the only answer
that is between {{{ 15 }}}
and {{{ 20 }}}, so that is correct