Amtrail trains provide efficient, nonstop transportation between Los Angeles and San Diego. Train A leaves Los Angeles headed toward San Diego at the same time that Train B leaves San Diego headed for Los Angeles, traveling on parallel tracks. Train A travels at a constant speed of 84 miles per hour. Train B travels at a constant speed of 92 miles per hour. The two stations are 132 miles apart. How long after they leave their respective stations do the trains meet?

2 answers

let x be the time taken for them to meet. D=v*t D1=84t, D2=92t The sum of the distances is 132miles.
Thus 84t + 92t = 132
and 176t = 132
or t = 132/176
t =3/4 hours
check:
84(3/4) + 92(3/4)
= 63 + 69
=132 miles
7 hrs