A freight train travels at 30 mph. If the freight train is 300 miles ahead of an express train traveling at 55 mph, how long will the express train take to overtake the freight train?

Question

Which equation could be used to find the number of miles the trains will travel?

30x = 55(x + 300)

x÷30 = (x - 300)÷55

x÷30 = (x + 300)÷55

Answer 1

55x = 30x + 300

55x -35x = 300

25x = 300

x = 300/25 = 12 hours to catch up

train going 30 miles per hour goes 30(12) = 360 miles

train going 55 miles per hour goes 55(12) = 660 miles = 300+360

none of the 3 alternatives works

the 1st would if you remove the parentheses and change the sign of 300 to: 30x = 55x -300

Answer 2

d = r * t

55t = 300 + 30t