Question 184850
For walking:
{{{d[w] = r[w]*t[w]}}}
For driving:
{{{d[d] = r[d]*t[d]}}}
given:
{{{d[w] = 10}}} km
{{{d[d] = 10}}} km
{{{t[w] + t[d] = 4}}} hrs
{{{r[d] = 30}}} km/hr
------------------------
{{{t[d] = 4 - t[w]}}}
{{{d[w] = r[w]*t[w]}}}
{{{10 = r[w]*t[w]}}}
and
{{{10 = 30*(4 - t[w])}}}
{{{10 = 120 - 30t[w]}}}
{{{30t[w] = 120 - 10}}}
{{{t[w] = 3.67}}} hr
{{{d[w] = r[w]*t[w]}}}
{{{10 = r[w]*3.67}}}
{{{r[w] = 2.727}}} km/hr answer
check answer:
{{{10 = 30*(4 - t[w])}}}
{{{10 = 30*(4 - 3.67)}}}
{{{10 = 30*.33}}}
{{{10 = 9.9}}} close enough