Answer:
probability that you and your 3 friends will be selected.
Step-by-step explanation:
A probability is the number of desired outcomes divided by the number of total outcomes.
In this question, the order in which the volunteers are chosen is not important, which means that the combinations formula is used to solve this question.
Combinations formula:
is the number of different combinations of x objects from a set of n elements, given by the following formula.

Desired outcomes:
You and the 3 friends(4 people), from a set of 4. So

Total outcomes:
20 people from a set of 20. So

Probability:

probability that you and your 3 friends will be selected.
<span> Perimeter is proportional to the side length by Perimeter, which 4 times the sides which equals 1/4 Perimeter.</span>
Answer:
first is 6/8 and second is 7/8
Step-by-step explanation:
The area of the actual castle would be 388,800 sq. ft.
We would multiply each of the sides of the scale model both by 180 to find the side lengths of the actual castle.
So...
180 x 4 = 720
180 x 3 = 540
If Area is equal to Length Times Width, all thats left to do is to multiply the two sides together.
720 x 540 = 388,800
Hope this helped! :D
Answer:
x1, x2 = 4.74 , -2.74
Step-by-step explanation:
To find the roots of a quadratic function we have to use the bhaskara formula
ax^2 + bx + c
x^2 - 2x - 13
a = 1 b = -2 c = -13
x1 = (-b + √ b^2 - 4ac)/2a
x2 =(-b - √ b^2 - 4ac)/2a
x1 = (2 + √ (2^2 - 4 * 1 * (-13)))/2 * 1
x1 = (2 + √ (4 + 52)) / 2
x1 = (2 + √ 56 ) / 2
x1 = (2 + 7.48) / 2
x1 = 9.48 / 2
x1 = 4.74
x2 = (2 - √ (2^2 - 4 * 1 * (-13)))/2 * 1
x2 = (2 - √ (4 + 52)) / 2
x2 = (2 - √ 56 ) / 2
x2 = (2 - 7.48) / 2
x2 = -5.48 / 2
x2 = -2.74