Let 
be the speed of train A, and let's set the origin in the initial position of train A. The equations of motion are
where 
are the positions of trains A and B respectively, and t is the time in hours.
The two trains meet if and only if 
, and we know that this happens after two hours, i.e. at 
Solving this equation for v we have
So, train A is travelling at 105 km/h. This implies that train B travels at
Step-by-step explanation:
is this the question you asked
20*2=40
40*50=2000
2000/60=33.33
about 33 hours by lifting by hand
Answer: Choice A
The number line graph is visually showing every number that is 19 or smaller; hence 
Note the use of a closed or filled in circle at the endpoint (in contrast to an open circle). This indicates we are including the endpoint 19 as part of the solution set, and that's why we go for "or equal to" as part of the inequality sign.
Step-by-step explanation:
S+T+U=180°{sum of angle of triangle}
- 68°+90°+U=180°
- U=180-158°
- U=22°
sin theta= p/h
sin22°=x/83
o.37=x/83
x=0.37×83
x=30.71
x=31
stay safe healthy and happy.
