Complete question :
From points A and B, the distance between which is 1020 mi, two trains left simultaneously towards each other. The speed of one train was 10 mph greater than the speed of the other one. In 5 hours the trains had not met yet and were 170 mi apart. Find the speed of the trains.
Answer:
Train A = 80 miles per hour
Train B = 90 miles per hour
Explanation:
Given that :
Distance between A and B = 1020
Let the speed of A = x
Speed of B = x + 10
Since they both left simultaneously;
Distance traveled after 5 hours will be :
Distance = speed * time
A = x * 5 = 5x
B = (x + 10) * 5 = 5x + 50
After the distance traveled by each of A and B, they are still 170 miles apart
Hence, distance covered after 5 hours ;
Total miles - miles left
1020 - 170 = 850 miles
Hence,
5x + 5x + 50 = 850
10x = 850 - 50
10x = 800
x = 80
Train A = 80 miles per hour
Train B = 80 + 10 = 90 miles per hour