Answer:
Just did it, had a good guess.
Step-by-step explanation:
.15x = 75
Divide both sides by .15 you get 500 minutes
The vertex is (-1, 2).
The equation of parabola:
where (h, k) is the vertex
We have h = -1 and k = 2.
Substitute:

2/7 is the probability that the first satellite sends a weak signal. That leaves 6, one of which sends a weak signal. So the probability that the second also sends a weak signal is 1/6. Combine these and we get 2/7×1/6=1/21.