X and Y are two stations which are 320 miles apart. A train starts at a certain time from X and travels towards Y at 70 mph. After 2 hours, another train starts from Y and travels towards X at 20 mph. At what time do they meet?

Answer 1

Hoping they are on different tracks ..
Time taken by faster train til they meet --- t
time taken by slower train til they meet --- t-2
distance covered by faster train = 70t
distance covered by slower train = 20(t-2)

70t + 20(t-2) = 320

take over

Answer 2

70t + 20t - 40 = 320
70t + 20t = 320 - 40
90t = 280
t = 280/90
t = 3.11

Answer 3

NO, error from
70t + 20t - 40 = 320
to
70t + 20t = 320 - 40

should be 70t + 20t = 320 + 40
90t = 360
t = 4