Two trains start from the same place at the same time. They travel i~ opposite directions. One

averages 60 miles per hour and the other averages 80 miles per hour. After how long will they
be 420 miles apart?

They each travel for t hours

distance covered by first train = 60 t miles
distance covered by 2nd train = 80t miles

60t+80t = 420
140t = 420
t = 3

3 hours.

wroung

To find out how long it will take for the two trains to be 420 miles apart, we need to use the formula:

Distance = Speed x Time

Let's assume that the time it takes for the two trains to be 420 miles apart is 't' hours.

For the first train traveling at 60 miles per hour, the distance it travels in 't' hours is 60t miles.

Similarly, for the second train traveling at 80 miles per hour, the distance it travels in 't' hours is 80t miles.

Since they are traveling in opposite directions, we can add their distances together:

60t + 80t = 420

Combining like terms:

140t = 420

To solve for 't', we divide both sides of the equation by 140:

t = 420 / 140

t = 3

Therefore, it will take 3 hours for the two trains to be 420 miles apart.