Question 64037
{{{d[p] / s[p] = d[c] / s[c]}}}
because {{{t[p] = t[c]}}} (they meet at the same time)
{{{(420 - x) / (c + 16) = x / c}}} given
{{{x / c = 5}}} given
{{{x = 5c}}}
{{{(420  - 5c) / (c + 16) = 5}}}
{{{420 - 5c = 5c + 80}}}
{{{10c = 340}}}
{{{c = 34}}}
Charlene's speed is 34 mi/hr