Let 
be the 20 marks of the boys, and 
be the 10 marks of the girls.
We know that the global mean was 70, meaning that
Multiplying both sides by 30 we deduce that the sum of the scores of the whole classroom is
By the same logic, we work with the marks of the boys alone: we know the average:
And we deduce the sum of the marks for the boys:
Which implies that the sum of the marks of the girls is 
And finally, the mean for the girls alone is
What answer are you looking for percents,fraction form, etc ?
The probability that a student who does not have a dog has a cat is 7/10.
<h3>What is the probability?</h3>
Probability determines the chances that a random event would happen. The odds that the random event would happen lies between 0 and 1.
The probability that a student who does not have a dog has a cat = number of students that do not have a dog but has a cat / total number of students that do not own a dog
= 7/10.
To learn more about probability, please check: brainly.com/question/13234031
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Explanation:
Let the equation be
a
⋅
x
2
+
b
⋅
x
+
c
. To factorize multiplication of a and c i.e. ac so that sum of factors, if ac is positive (and difference if ac is negative) is equal to b. Now split b into these two components and factorization will be easy.
The total time taken for round trip will be: (f+g)(x) = 14x+11
Step-by-step explanation:
Given
In order to find the round-trip time, we have to add both functions to represent the time taken to travel east and the time taken to travel to west.
Hence,
The total time taken for round trip will be: (f+g)(x) = 14x+11
Keywords: Functions, variables
Learn more about functions at:
#LearnwithBrainly
