This is esay to do when you realize the the speed of mowing is addtive. This is if John mows at 1 lawn / (2/3) hour and Gerge mows at 1 lawn / 1hour, the total speed of mowing is:
1 / (2/3) + 1 = 3/2 + 1 = 5/2
=> 5/2 of lawn per hour
Now, the time is calcualted as the amount of lawn divided by the speed:
1 lawn / (5/2 lawn/hour) = 2/5 hour.
Answer: 2/5 of an hour.
Answer:
Step-by-step explanation:
1) For each situation to grow or decay by a constant percent rate, it must be exponential. Therefore, the correct examples are
A. The number of cars sold doubles every year. It is a 200% growth every year.
D. Each time you start a car engine the remaining engine life decreases by 0.0075%. A case of decay
E. The number of people creating cat videos increases by 15% percent every year.
F. Computer technology increases by a factor of 3 every five years.
2) this is a case of exponential decay. The expression for exponential decay is
y = b(1 - r)^t
y = final value
b = initial value
r = decay rate
t = time
Given that
r = 10% = 10/100 = 0.1
b = 50 kilograms
y = W kilograms
The relationship is
W = 50(1 - 0.1)^t
W = 50(0.9)^t
slope = difference in y / difference in x
slope = 12 -11 / 2 -6
slope = 1 / -4
slope = -1 / 4 or
-.25
Answer:
B. 48x - 56
Step-by-step explanation:
