Solution: The speed of old freight train is 0.5 miles per minute and the speed of new dart express train is 1.5 miles per minute.
Explanation:
Let the speed of old freight train is x miles per minute and the speed of new dart express train is y miles per minute.
It is given that the speed of the dart express train is three times faster than the freight train. So, it can be written as,
....(1)
The trains are moving towards the opposite directions, therefore the distance between them is increased at the speed of
miles per minute.

The distance between both train in 15 minutes is represented by
.
According to the given information the distance between trains is 30 miles in 15 minutes.


Use equation (1) and put 



Put this value in equation (1), to find the value of y.


Therefore, the The speed of old freight train is 0.5 miles per minute and the speed of new dart express train is 1.5 miles per minute.
We dont know how many people were originally in the group.
Answer:
78º
Step-by-step explanation:
<u>Note</u> : -
In mathematics, the reference angle is defined as the acute angle and it is measuring less than 90 degrees. It is always the smallest angle, and it makes the terminal side of an angle with the
x - axis.
<u>S</u><u>t</u><u>e</u><u>p</u><u> </u><u>1</u> : -
Find where 192º lies in which quadrant.
192º lies in 3rd quadrant ( between
180º and 270º )
<u>S</u><u>t</u><u>e</u><u>p</u><u> </u><u>2</u> : -
Subtract : 270 - 192
270 - 192 = 78º
( Since, 192º is greater than 180º, is subtracted from 270º )
<u>A</u><u>n</u><u>s</u><u>w</u><u>e</u><u>r</u> : -
78º is the reference angle for 192º.