This is for the first answer and to be honest just use Desmos if you don’t have a graphing calculator
2.4 * 60 = 144 total minutes
X+y=4 y=3x
x+3x=4
4x=4
divide both sides by 4
x=1
Well you can start by drawing a triangle with the information
the size of angle B can be found using the Law of Sine

the size of angle C can be found using angle sum of a triangle.
The length of side c can be found using the Law of Cosines

hope it helps


keep in mind, that "t" is the time when the train at A station, left towards B station
they met, at some time "t", and by the time that happened, train from A
which started 3 hours earlier, had already covered "d" distance,
whatever that is
and the train coming from B, covered, 600-d, or the difference