Answer: 37 units
Step-by-step explanation:
This also works as the height of the triangle.
This also works as the base of the triangle.
Let's call pink ''a'', and blue ''b''. The side we're looking for ''c'' is the hypothenuse.
To find the values of a and b, use the area formula of a square and solve for a side. In this case, since we're going to need the squared values, this step can be omitted.
![s=\sqrt[]{A}](https://tex.z-dn.net/?f=s%3D%5Csqrt%5B%5D%7BA%7D)
Let's work with Blue.
![s=\sqrt[]{144units^2} \\s=12units](https://tex.z-dn.net/?f=s%3D%5Csqrt%5B%5D%7B144units%5E2%7D%20%5C%5Cs%3D12units)
Now Pink.
![s=\sqrt[]{1225units^2}\\s=35units](https://tex.z-dn.net/?f=s%3D%5Csqrt%5B%5D%7B1225units%5E2%7D%5C%5Cs%3D35units)
So we have a triangle with a base of 35 units and a height of 12 units.
Now let's use the pythagoream's theorem to solve.
![c^2=a^2+b^2\\c=\sqrt[]{a^2+b^2} \\c=\sqrt[]{(12units)^2+(35units)^2}\\c=\sqrt[]{144units^2+1225units^2}\\ c=\sqrt[]{1369units^2}\\ c=37units](https://tex.z-dn.net/?f=c%5E2%3Da%5E2%2Bb%5E2%5C%5Cc%3D%5Csqrt%5B%5D%7Ba%5E2%2Bb%5E2%7D%20%5C%5Cc%3D%5Csqrt%5B%5D%7B%2812units%29%5E2%2B%2835units%29%5E2%7D%5C%5Cc%3D%5Csqrt%5B%5D%7B144units%5E2%2B1225units%5E2%7D%5C%5C%20c%3D%5Csqrt%5B%5D%7B1369units%5E2%7D%5C%5C%20c%3D37units)
Answer: the speed of the boat on the lake is 9 mph
Step-by-step explanation:
Let x represent the speed of the boat on the lake or in still water.
The speed of the current in a river is 6 mph. This means that if the boat goes upstream against the speed of the current, its total speed would be (x - 6)mph. If the boat goes downstream against the speed of the current, its total speed would be (x + 6)mph.
Time = distance/ speed
Every day, his route takes him 22.5 miles each way against the current and back to his dock, and he needs to make this trip in a total of 9 hours. This means that the time taken to travel upstream is
22.5/(x - 6). The time taken to travel downstream is
22.5/(x + 6)
Since the total time is 9 hours, it means that
22.5/(x - 6) = 22.5/(x + 6)
Cross multiplying, it becomes
22.5(x + 6) + 22.5(x - 6) = 9
Multiplying through by (x + 6)(x - 6), it becomes
22.5(x - 6) + 22.5(x + 6) = 9[(x + 6)(x - 6)]
22.5x - 135 + 22.5x + 135 = 9(x² - 6x + 6x - 36)
22.5x + 22.5x = 9x² - 324
9x² - 45x - 324 = 0
Dividing through by 9, it becomes
x² - 5x - 36 = 0
x² + 4x - 9x - 36 = 0
x(x + 4) - 9(x + 4) = 0
x - 9 = 0 or x + 4 = 0
x = 9 or x = - 4
Since the speed cannot be negative, then x = 9
So, r' (the new r) becomes kr, and h'=h*k,
so V' = pi * (r')^2*h' = pi * (r*k)^2*(h*k) = pi*r^2*h*k^3 = V * k^3
Convinced?
Answer:
Upper quartile: 38
Lower quartile: 19
The answer is in the picture
