There are a couple of ways to think about this.
1) Weight the speed by the time and compute the weighted average.
(60*2.5 + 75*1.5)/(2.5 + 1.5) = 65.625
Her average rate of speed is 65.625 mph.
2) Consider distance and time.
distance = speed * time
distance₁ = speed₁ * time₁
distance₂ = speed₂ * time₂
total distance = distance₁ + distance₂
total time = time₁ + time₂
And the average speed is given by
average speed = (total distance)/(total time)
Using the above formulas, we have
distance₁ = 60 mi/h * 2.5 h = 150 mi
distance₂ = 75 mi/h * 1.5 h = 112.5 mi
total distance = 150 mi + 112.5 mi = 262.5 mi
total time = 2.5 h + 1.5 h = 4.0 h
average speed = (262.5 mi) / (4.0 h) = 65.625 mi/h
Bette's average rate of speed is 65.625 mph.
Answer:
A.
m = -1
Step-by-step explanation:
Slope Formula: 
Simply plug in your 2 coordinates into the formula to find slope <em>m</em>:
m = (6 - 4)/(2 - 4)
m = 2/-2
m = -1
let's label each pump A, B, and C, just for convenience. A fills the tank by 1/50 every minute, B fills the tank by 1/60 every minute, and C drains it by 1/75 every minute. Now we can put them all into one function: t(1/50 + 1/60 - 1/75) = 1, where t = our time in minutes and 1 = the tank being full.
next, we solve for t: t = 300/7 minutes, or approximately 42.86 minutes.
500 each because there's only 2 boxes
You would have 14.76 trees cut
