Train A leaves at 60mph. Eight hours later train B leaves at 70mph. How long does it take for train B to catch

Question

up with train A?

Answer 1

Train A speed, Va = 60mph
Train B speed, Vb = 70mph
Train B leave after 8 hours trains A leaves

Let say t = time for Train B to catch
Va x (8 + t) = Vb x t
60 (8 + t) = 70 t
10 t = 480
t = 48 hours

Answer 2

After 8 hours, train A has travelled 8*60 = 480 miles
After 8 hours, the distance from the station for train A is 480+(60*h)
[h being the number of hours]
For train B, the distance is 70*h

When B has caught up with A, the distances are the same i.e.

70h=480+60h

[-60h]

10h=480

[/10]

h=48

After 8 hours it takes b 48 hours to catch up making a grand total of 56 hours from when train a started

Answer 3

after 8 hours the distance between the trains = 8 * 60
= 480 mile

the distance decreases in a rate of 10mph

so it takes 480/10 = 48 hours
= 2 days

Answer 4

60t = x

70(t - 8) = x
70t - 560 = x
70t - 560 = (60t)
10t = 560
t = 56

As this is in mph, t is in hours.

To check, after 56 hours, train A will have traveled 3360 miles. But train B left 8 hours later...so 56 - 8 = 48. 70 * 48 = 3360. As they're the same distance from the origin now, it's correct.

It takes 48 hours for train B to catch up

Answer 5

it the time practice B has traveled is t, then A has traveled t+4 hours. In each and every of those hours, A travels 30 mi, so its distance at any time is 30(t+4). B is going 40t miles. whilst B catches up whilst 40t=30(t+4) 40t=30t+one hundred twenty 10t=one hundred twenty t=12 B has then long gone 12 hours and moved 480 miles. A went sixteen hours, and 30*sixteen=480 miles.

Answer 6

Assuming they travel at a constant speed
By the time B leaves A has traveled 8x60 miles = 480 miles
B travels 10 mph faster so it will take 48 hours to catch up.
Or to determine the time they have traveled the same distance
A has traveled 480+60z where z is the hours until they have traveled the same distance
B travels 70z
So 480+60Z=70Z
or 480=10z
z = 48

Answer 7

It really depends upon the Dispatcher and the Engineer. If the Dispatcher doesn't let train A go anywhere not long. If the Engineer doesn't keep the train at the specified speed (which is hard to do since they are long and heavy trust me on this one check my screen name out) it will always vary. So to answer your question there is no way of telling , because the variables are never constant

Answer 8

When B leaves, it has 480 miles of catching up to do.

It does so at a rate of 10 miles per hour.

Sooo....

Answer 9

the "super answer" is 6.8571428 but 6.85 or 6.8 would also do