AMC 12 Mock Exam 5 Problem 3

Problem 3 of 25

The mean score of the $10$ students in a class on a quiz is $72$ . Two students who were absent take the quiz later. One of them scores $90$ , and after both new scores are included, the mean of all $12$ scores is $74$ . What did the other student score?

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Solution

The original total is $10\cdot72=720$ , and the new total is $12\cdot74=888$ . The two new scores add to $888-720=168$ , so the other student scored $168-90=\boxed{78}$ .

Tagged: means

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