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
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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)
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c) The cheetah's average rate was 50 10/11 mph ≈ 50.91 mph.
Anita's account had linear growth
Miguel's account had exponential growth.
Miguel's account grew faster because exponential growth is faster than linear growth
Answer:
y = -13.5
x = -10.5
Step-by-step explanation:
Hi there!
Let the two numbers be equal to <em>x</em> and <em>y</em>.
The difference of two numbers is 3 ⇒ x - y = 3
Their sum is - 24 ⇒ x + y = -24
Solve using elimination:
x - y = 3
x + y = -24
Add the two equations:
x + x - y + y = 3 - 24
2x = -21
x = -10.5
Solve for y:
-10.5 - y = 3
- y = 3 + 10.5
y = -13.5
I hope this helps!
Answer:
Step-by-step explanation:
L= 3W
Perimeter = 2(l+w) = 40
2(3w+w) = 40
2*4w = 40
8w =40
w = 5
l = 3*5 = 15
Answer: 10%
Step-by-step explanation:
Since the shopkeeper purchased 60 pencil boxes for 4,500, he purchased them at the rate of:
= 4500 / 60
= 85 per pencil box
If the shopkeeper sold them at the rate of 4,125 for 50 pencil boxes, then he sold them at the rate of:
= 4125 / 50
= 82.50 per pencil box.
Therefore the percentage profit will be:
= Gain / Cost price × 100
= (82.50 - 75) / 75 × 100
= 7.5/75 × 100
= 10%
