Question 51645
Where will the 1st train be at 12:15?
It will have travelled for 15 min at 90 mi/hr
r*t = d
90 mi/hr * 1/4 hr = 22.5 mi from Bridgton
Now it is (450 - 22.5) mi from Cogsville
Now the 2nd train leaves, and both will travel for the same
amount of time until they meet
{{{t(1) = t(2)}}}
{{{d(1)/r(1) = d(2) / r(2)}}}
{{{d(1) / 90 = d(2) / 100}}}
{{{d(1) = .9*d(2)}}}
{{{d(1) + d(2) = 450 - 22.5}}}
{{{d(1) + d(2) = 427.5}}}
{{{.9*d(2) + d(2) = 427.5}}}
{{{1.9*d(2) = 427.5}}}
{{{d(2) = 225}}}
{{{d(1) = 427.5 - 225}}}
{{{d(1) = 202.5}}}
{{{t(1) = t(2)}}}
{{{202.5 / 90 = 225 / 100}}}
{{{2.25 = 2.25}}}
So, the trains travel for 2.25 hours until they meet. That is with
a starting time of 12:15 pm
So, they meet at 12:15 pm + 2 1/4 hrs = 2:30 pm