Answer:
B. 100π
Step-by-step explanation:
The surface area of a sphere is given by
SA = 4 pi r^2
The radius is 5
SA = 4 * pi * r^2
SA = 4 * pi * 25
SA = 100 pi
9514 1404 393
Answer:
a) average rate = (total distance)/(total time)
b) Rave = 2·R1·R2/(R1 +R2)
c) cheetah's average rate ≈ 50.91 mph
Step-by-step explanation:
a) Let AB represent the distance from A to B. Let t1 and t2 represent the travel times (in hours) on leg1 and leg2 of the trip, respectively. Then the distances traveled are...
First leg distance: AB = 70·t1 ⇒ t1 = AB/70
Second leg distance: AB = 40·t2 ⇒ t2 = AB/40
The average rate is the ratio of total distance to total time:
average rate = (AB +AB)/(t1 +t2)
average rate = 2AB/(AB/70 +AB/40) = 2/(1/70 +1/40) = 2(40)(70)/(70+40)
average rate = 560/11 = 50 10/11 . . . mph
__
No equations are given, so we cannot compare what we wrote with the given equations. In each step of the solution, we have used the rules of algebra and equality.
b) For two rates over the same distance (as above), the average is their harmonic mean:
average rate = 2r1·r2/(r1+r2)
__
c) The cheetah's average rate was 50 10/11 mph ≈ 50.91 mph.
P ( A ) = 0.45 - probability that the land has oil,
P ( B ) = 0.8 - probability that the test predicts it
P ( A ∩ B ) = P ( A ) · P ( B ) = 0.45 · 0.8 = 0.36
Answer: The probability that the land has oil and the test predicts it is 36 %.
I can't see the figure entirely. To solve for the perimeter you need to know the height!
