SOLUTION: Camellia took her geography test. She scored 100 on her exam which was found to raise the class average on the test from 74 to 76. ( before adding her school the average was 74 ) h

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Question 1168771: Camellia took her geography test. She scored 100 on her exam which was found to raise the class average on the test from 74 to 76. ( before adding her school the average was 74 ) how many students including Camelia took the test?
Answer by ikleyn(52787) About Me  (Show Source):
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Camellia took her geography test. She scored 100 on her exam which was found to raise the class average on the test
from 74 to 76. ( before adding her school the average was 74 ) how many students including Camelia took the test?
~~~~~~~~~~~~~~ 


Let  n = "how many students including Camelia took the test".


Since the average score was 74 for (n-1) students (before Camelia took the test)

the total scores were  74*(n-1)  at that time.


Camelia contributed 100 scores to the total, so now the average is


    76 = %2874%2A%28n-1%29%2B100%29%2Fn.


From this equation


    76n = 74*(n-1) + 100,    or

    76n = 74n - 74 + 100,

which gives

    76n - 74n = 26

       2n     = 26

        n     = 26/2 = 13.


ANSWER.  13 students, including Camelia.

Solved.

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