Average speed=Total Distance Covered\<span>Total time take<span>n
T.D=240+180=420
T.T=2.5+2=4.5
420\4.5=93.3 km\h
answer=D</span></span>
it is b -30 plz give me brainlist
Answer: option a.
Step-by-step explanation:
By definition, we know that:

Substitute
into the first equation, solve for the cosine and simplify. Then, you obtain:

As
then
:

Now we can find
:
