Calculating Number of Students in Second Class: Average Score Statistics

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To determine the number of students in the second class, the average scores of both classes were used. The first class had 30 students with an average score of 80, while the second class had an average score of 70, resulting in a combined average of 74. The correct calculation involves using the total number of students from both classes, leading to the conclusion that there are 45 students in the second class. The initial misunderstanding stemmed from incorrectly dividing by 2 instead of the total number of students. The final answer confirms that 45 students were tested in the second class.
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Homework Statement



Two classes made a test.
In one class there were 30 students, and the average score was 80.
In the second class, the average score was 70.
The average of both classes was 74.
How many students were tested in the other class?

Homework Equations


The solution is 45 students

The Attempt at a Solution


Attached. I'm getting a minus, clearly I'm off :/

Can anyone clue me in?
 

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You are dividing by 2, where instead it should be the total number of students in the combined classes i.e. 30+x
 
Ah... I see the errors of my ways. Earlier I did 30x and got 1.11, I forgot that's not the total number of students..my bad. Thank you much.
 

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