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maxonik [38]
3 years ago
15

Al can wash a car in 60 minutes, and bill can wash a car in 30 minutes. cathy can wash a car in 20 minutes. how long, in minutes

, would it take the 3 of them to wash a car, working together?
a. 10

b. 36

c.

d. 110
Mathematics
1 answer:
choli [55]3 years ago
3 0
B) 36

To figure this out you need to average the numbers. To average them you add them all up and divide by how many are there.
(60+30+20)/3
(90+20)/3
110/3
36
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To visit the top of the Empire State Buidling, a ticket
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Answer:

Step-by-step explanation:

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(50-20/20)*100=(30/20)*100=150

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7 0
3 years ago
Consider the circle of radius 5 centered at (0, 0). Find an equation of the line tangent to the circle at the point (3, 4) in sl
Wittaler [7]

Answer:

\displaystyle y= -\frac{3}{4} x + \frac{25}{4}.

Step-by-step explanation:

The equation of a circle of radius 5 centered at (0,0) is:

x^{2} + y^{2} = 5^{2}.

x^{2} + y^{2} = 25.

Differentiate implicitly with respect to x to find the slope of tangents to this circle.

\displaystyle \frac{d}{dx}[x^{2} + y^{2}] = \frac{d}{dx}[25]

\displaystyle \frac{d}{dx}(x^{2}) + \frac{d}{dx}(y^{2}) = 0.

Apply the power rule and the chain rule. Treat y as a function of x, f(x).

\displaystyle \frac{d}{dx}(x^{2}) + \frac{d}{dx}(f(x))^{2} = 0.

\displaystyle \frac{d}{dx}(2x) + \frac{d}{dx}(2f(x)\cdot f^{\prime}(x)) = 0.

That is:

\displaystyle \frac{d}{dx}(2x) + \frac{d}{dx}\left(2y \cdot \frac{dy}{dx}\right) = 0.

Solve this equation for \displaystyle \frac{dy}{dx}:

\displaystyle \frac{dy}{dx} = -\frac{x}{y}.

The slope of the tangent to this circle at point (3, 4) will thus equal

\displaystyle \frac{dy}{dx} = -\frac{3}{4}.

Apply the slope-point of a line in a cartesian plane:

y - y_0 = m(x - x_0), where

  • m is the gradient of this line, and
  • (x_0, y_0) are the coordinates of a point on that line.

For the tangent line in this question:

  • \displaystyle m = -\frac{3}{4},
  • (x_0, y_0) = (3, 4).

The equation of this tangent line will thus be:

\displaystyle y - 4 = -\frac{3}{4} (x - 3).

That simplifies to

\displaystyle y= -\frac{3}{4} x + \frac{25}{4}.

3 0
3 years ago
How does the amount of principal affect the number of years the rule of 72 predicted in the example above?
NeTakaya

Answer:

If the interest per quarter is 4% (but interest is only compounded annually), then it will take (72 / 4) = 18 quarters or 4.5 years to double the principal. If the population of a nation increases at the rate of 1% per month, it will double in 72 months, or six years.

Step-by-step explanation:

hope this helps

8 0
2 years ago
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mel-nik [20]

Answer:

Eu não sei cara, sinto muito, cara, não me denuncie ou você é apenas um idiota metido

Step-by-step explanation:

Eu não sei cara, sinto muito, cara, não me denuncie ou você é apenas um idiota metido

5 0
3 years ago
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Hence x is 7 seconds

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3 years ago
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