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3 years ago

4 people can dig a hole in 3 hours. How long does it take 9 people.

Mathematics

2 answers:

maw [93]3 years ago

7 0

Answer:

9 people is 9/4 = 2.25 times more people than 4 people. So, they can do it faster. 3 hours/2.25 = 1.33 hours 1.33 hours x 60 minutes/hour = 80 minutes

Step-by-step explanation:

ad-work [718]3 years ago

6 0

Answer: 1 hour 20 minutes

<u>Step-by-step explanation:</u>

Let's figure out how long it would take 1 person to dig the hole and then divide that number by 9 (since they are sharing the workload).

$\dfrac{1}{4}x=3\qquad \implies \qquad x = 12\quad \text{It takes 12 hours for 1 person}\\\\\\\dfrac{12\ \text{(for 1 person)}}{9\ \text{(people)}}\quad =1\dfrac{1}{3}\quad =\large\boxed{1\ hour\ 20\ minutes}$

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The diameter of a sphere is 4 centimeters. Which represents the volume of the sphere?

soldier1979 [14.2K]

Answer:

32 $\pi$ /3 cm³

Step-by-step explanation:

If the diameter is 4 cm, then the radius is 2 cm.

Use the sphere volume formula:

V = 4/3 $\pi$ r³

Plug in the radius and solve:

V = 4/3 $\pi$ (2)³

V = 4/3 $\pi$ (8)

V = 32 $\pi$ /3

So, the volume of the sphere is 32 $\pi$ /3 cm³

3 0

3 years ago

Select the lengths in centimeters that would form a right triangle

Ivenika [448]

Answer:

9, 40 and 41

Step-by-step explanation:

All right triangle have lengths that follow the Pythagorean Theorem (a²+b² = c²). Right triangles have one angle equal to 90°. The two shorter sides form the right angle and the side opposite the right angle is called the hypotenuse.

Using the lengths given, we can use guess and check to see what sum of two sides squared would equal a third side, or just plug them into the equation: a²+b² = c² and see what lengths fit this equation.

I recommend starting with squares you are familiar with:

9² + 40²= 81 + 1600 = 1681

Now, take the √1681 to find the length of 'c', or the hypotenuse:

√1681 = 41

Since these three lengths fit the Pythagorean Theoreom, the would form a right triangle.

4 0

3 years ago

Help asap pls

Svet_ta [14]

Answer:

Eating dinner and eating dessert are dependent events because

P(dinner) . P(dessert) = 0.9 × 0.6 = 0.54 which is not equal to

P(dinner and desert) = 0.5 ⇒ answer A

Step-by-step explanation:

* Lets study the meaning independent and dependent probability

- Two events are independent if the result of the second event is not

affected by the result of the first event

- If A and B are independent events, the probability of both events

is the product of the probabilities of the both events

- P (A and B) = P(A) · P(B)

* Lets solve the question

∵ There is a 90% chance that a person eats dinner

∴ P(eating dinner) = 90/100 = 0.9

∵ There is a 60% chance a person eats dessert

∴ P(eating dessert) = 60/100 = 0.6

- If eating dinner and dating dessert are independent events, then

probability of both events is the product of the probabilities of the

both events

∵ P(eating dinner and dessert) = P(eating dinner) . P(eating dessert)

∴ P(eating dinner and dessert) = 0.9 × 0.6 = 0.54

∵ There is a 50% chance the person will eat dinner and dessert

∴ P(eating dinner and dessert) = 50/100 = 0.5

∵ P(eating dinner and dessert) ≠ P(eating dinner) . P(eating dessert)

∴ Eating dinner and eating dessert are dependent events because

P(dinner) . P(dessert) = 0.9 × 0.6 = 0.54 which is not equal to

P(dinner and desert) = 0.5

8 0

3 years ago

On a piece of paper, graph f(x) = 4 x (0.5)^x

tangare [24]

The complete question is

"On a piece of paper, graph f(x) = 4. (0.5)^x Then determine which answer choice matches the graph you drew."

The given function is an exponential function. The graph of option C is the correct answer.

<h3>What are exponential functions?</h3>

When the expression of function is such that it involves the input to be present as an exponent (power) of some constant, then such function is called exponential function.

There usual form is specified below. They are written in several such equivalent forms.

For example, $y^x$