North American : South American : European
9 : 5 : 2
Multiply all by 10
90 : 50 : 20
The answer is 50 South American butterflies.
The viewer mistakenly determined that one of the equations in the system should be 2 x + y = 28. Instead modifications should have been made before applying the equation.
<h3>What is an Equation ?</h3>
An equation is a mathematical statement formed when two algebraic expressions are equated using an equal sign.
Total Questions = 20
Total Points = 28
Correct Answers = +2 points
Incorrect Answers = -1 point
The viewer represents the correct answers with x and the incorrect ones with y.
x+y = 20
for every correct answers 2 points;
and for every incorrect answers, -1 point
This can be written as
2x-y = 28
The viewer's mistake is that; instead of subtracting total incorrect points from the correct points, the viewer added them together;
now
2x-y = 28
x+y = 20
On adding the equations
]3x = 48
x = 16
y = 4
This means that the contestant answered 16 questions correctly and 4 questions incorrectly
The viewer mistakenly determined that one of the equations in the system should be 2 x + y = 28.
To know more about Equation
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F x L = 3x10^10
L = 1x10^-11
F= 3x10^10 / 1x10^-11 = 3x10^21 unit
Answer:
39
Step-by-step explanation:
About 99.7% of vehicles whose speeds are between 59 miles per hour and 77 miles per hour.
Empirical rule states that for a normal distribution, 68% lie within one standard deviations, 95% lie within two standard deviations, and 99.7% lie within three standard deviations of the mean.
Given that mean (μ) = 68 miles per hour, standard deviation (σ) = 3 miles per hour.
68% lie within one standard deviation = (μ ± σ) = (68 ± 3) = (65, 71).
Hence 68% of the vehicle speed is between 65 miles per hour and 71 miles per hour.
95% lie within two standard deviation = (μ ± 2σ) = (68 ± 2*3) = (62, 74).
Hence 95% of the vehicle speed is between 62 miles per hour and 74 miles per hour.
99.7% lie within three standard deviation = (μ ± 3σ) = (68 ± 3*3) = (59, 77).
Hence 99.7% of the vehicle speed is between 59 miles per hour and 77 miles per hour.
Find out more at: brainly.com/question/14468516
