Answer:
30
Step-by-step explanation:
Perimiter is the length of each side added up. We don't know the side lengths, but we can find it.
It tells us the volume and height, and we use the side lengths to find volume, so lets use that. I'm not sure how you have learned how to find the area of a pentagon, but I am going to use the formula google shows. I am going to use x for the side length
A = sqrt(25+10sqrt(5))x^2/4
Now, for any right prism you take the volume of you get the area of the base and multiply it by the height So we can work that out to find the sides.
A*h = V
(sqrt(25+10sqrt(5))x^2/4)*14 = 840
(sqrt(25+10sqrt(5))x^2/4) = 60 (Divide both sides by 14)
sqrt(25+10sqrt(5))x^2 = 240 (Multiply both sides by 4)
x^2 = 34.874 (Divide both sides by sqrt(25+10sqrt(5))
x = 5.905 (square root of both sides)
Now we have the length of one side. Since there are five sides we multiply that by 5.
5 * 5.905 = 29.525 So it rounds up to 30.
Let me know if there is something you did not understand.
The age of the father is 57 years old
<h3>Calculating mean of a population</h3>
Total age = Average age x Population
Average of the four children = 15
Population = 4
Total age of the four children = 15 x 4
Total age of the four children = 60 years
If the parents are added:
Population = 6
Average age = 25
Total age = 25 x 6
Total age = 150 years
Total age of the parents = 150 - 60
Total age of the parents = 110 years
The father is 4 years older than his wife
Let the age of the father be x
The age of the wife = x - 4
x + x - 4 = 110
2x = 114
x = 114/2
x = 57
Therefore, the age of the father is 57 years old
Learn more on The mean of numbers here: brainly.com/question/20118982
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Simple system of equations problem,
m = member
n = nonmember
1m + 3n = 210
2m + 1n = 120
You can multiply the top equation by 2 to get:
2m + 6n = 420
2m + 1n = 120
Then you can subtract the two equations and the members will cancel out (2m - 2m = 0)
and get:
5n = 300 so dividing by 5 on both sides you get
n = 60
then you can plug in the value of 60 into one of the equations
2m + 1(60) = 120
So subtracting 60 u get
2m = 60
member = 30
nonmembers = 60
I never been good at that either