Question 516334
A car left seattle traveling 45mph. A second car left from the same place one hour later on the same road traveling 60mph. How long will it take the second car to catch up with the first car. Which of these is the correct second eqaution for the problem?


Car A Data
==========
Speed = 45mph
Time = t hour
Distance covered = x miles

Distance = speed*time
x=45*t
x=45t.............(1)


Car B Data
==========
Speed = 60mph
Time =t-1(hour)
Distance covered = x
Distance = Speed * time
x=60*(t-1)


Both cars will cover same distance

45t=60*(t-1)
45t=60t-60
45t-60t=60
-15t=-60
-15t/-15=-60/-15
t=4 hours

Car A travel time 4 hours and Car B travel time 3 hours.
After 3 hours of leaving same place Car B will catch Car A

Check
========

Car A Data
==========
Speed = 45mph
Time = 4 hour
Distance covered = x miles

Distance = speed*time
x=45*4
x=180 miles

Car B Data
==========
Speed = 60mph
Time =t-1=4-1=3(hour)
Distance covered = x
Distance = Speed * time
x=60*3
x=180 miles