Answer:
15 mph
Step-by-step explanation:
Given: Boat took 2 hours to reach Town A going upstream.
Speed of stream= 3 mph
Time taken to reach back home= 1 hours 20 minutes
Lets assume distance covered one side be "d" and speed of boat in still water be "s".
∴ Speed of boat in upstream= 
Speed of boat in downstream= 
Also converting into fraction of time taken to reach back home.
Remember; 1 hour= 60 minutes
∴ Time taken to reach back home= 
Converting time given into fraction= 
hence, Time taken to reach back home is 
Now forming equation of boat travelling upstream and downstream, considering distance remain constant.
We know, 
⇒ 
Using distributive property of multiplication
⇒
subtracting both side by 
⇒
Adding both side by 6
⇒ 
taking LCD as 3
⇒ 
Multiplying both side by 
⇒
∴s= 15 mph
Hence, 15 mph is the speed of the boat in still water.
The fare of $(20 - 2.5) = $17.5 will maximize the total fare.
<h3>What is Differentiation?</h3>
Differentiation means the rate of change of one quantity with respect to another. The speed is calculated as the rate of change of distance with respect to time.
Here, The operator for a round-trip fare of $20, carries an average of 500 people per day.
It is estimated that 20 fewer people will take the trip, for each $1 increase in fare.
for $x increase in fare, 20x less people will take the trip and at that time the total fare F is given by
f(x) =(20 + x)(500 - 20x)
f (x) = 10000 + 100x - 20x²
For f(x) to be maximum, the condition is dy/dx = 0
100 - 40x = 0
⇒ x = 2.5
Thus, the fare of $(20 - 2.5) = $17.5 will maximize the total fare.
Learn more about Differentiation from:
brainly.com/question/24062595
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Answer:
8
Step-by-step explanation:
1 2 3 4 5 6 7 8 quick math
You need to look at the x values when you calculate that.
There is a line which goes from -2 to 0. Another line at 0 to 4 and the last line is 7 to infinity.
You can combine the first two and get B) (-2, 4] and [7, infinity)
Answer:
Step-by-step explanation:
We can calculate this confidence interval using the population proportion calculation. To do this we must find p' and q'
Where p' = 14/100= 0.14 (no of left handed sample promotion)
q' = 1-p' = 1-0.14= 0.86
Since the requested confidence level is CL = 0.98, then α = 1 – CL = 1 – 0.98 = 0.02/2= 0.01, z (0.01) = 2.326
Using p' - z alpha √(p'q'/n) for the lower interval - 0.14-2.326√(0.14*0.86/100)
= -2.186√0.00325
= -2.186*0.057
= 12.46%
Using p' + z alpha √(p'q'/n)
0.14+2.326√(0.14*0.86/100)
= 0.466*0.057
= 26.5%
Thus we estimate with 98% confidence that between 12% and 27% of all Americans are left handed.
