Answer: The average was 9 years old find the average age of both groups is 10 years old.
Step-by-step explanation:
Formula foe average : 
Given : The first group of students consists of 10 and their average age was 13 years old.
i.e. 
(1)
The next group consisted of 30 students and their average was 9 years old.
i.e. 
(2)
Then from (1) and (2) , the sum of both groups (first group and next group )students = 130+270 =400
Combined students of both groups (first and next group )= 10+30=40
Now , the average of both groups =
Hence, the average was 9 years old find the average age of both groups is 10 years old.
Using the given percentages, it is found that the probability that a randomly chosen plant is detected incorrectly is 0.02965 = 2.965%.
<h3>Percentages:</h3>
The percentages associated with an incorrect detection are:
- 2% of 3.5%(have the protein).
- 3% of 96.5%(do not have the protein).
Hence:
The probability that a randomly chosen plant is detected incorrectly is 0.02965 = 2.965%.
You can learn more about percentages and probabilities at brainly.com/question/25960993
<h3>
Answer: 5</h3>
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Explanation:
Apply the difference of squares rule
x^2 - y^2 = (x-y)(x+y)
x^2 - y^2 = (5)(1)
x^2 - y^2 = 5
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Alternatively, you can solve the system
for x and y to get (x,y) = (3,-2).
Then compute x^2-y^2 = 3^2-(-2)^2 = 9-4 = 5
Answer: Train 2 is traveling 4 miles per hour faster than train 1.
Step-by-step explanation:
