Posted by Simon on Tuesday, May 11, 2010 at 5:43pm.
In a test, the average was 74 points/100 points. After the test, three of students relocate. Then the average was 75 points/100. The circumstances of the students were 6:5:3. How many points did the three students have?
I know the answere is 45, 75 and 90, but can you write the operation?

math  PsyDAG, Wednesday, May 12, 2010 at 7:48pm
Mean = (sum of scores)/number of scores
If I understand your problem correctly, the ratio of the three scores are 6:5:3 and the mean of the three = 75. If that is what you are saying, then:
75 = (6x + 5x + 3x)/3 = 14x/3
14x = 225
Solve for x.
However, this does not give you the answers you indicate. Sorry. Can you state the problem more clearly?
Answer This Question
Related Questions
 math  In a test, the average was 74 points/100 points. After the test, three of...
 Algebra  Students get two grades for a test in an introductory psychology ...
 statistic  The average score on a standardized test is 750 points with a ...
 statistics  The average score on a standardized test is 500 points with a ...
 Statistics  A student wants to test her hypothesis she gives each of her ...
 Algebra  The 22 students present for a recent test in Ms. Huangâ€™s class had an ...
 Algebra 1  A teacher knows that 80% of her students will score no more than 5 ...
 math  Mr. Noonan told Vic that his test had 38 problems worth a total of 100 ...
 Math Help  In three math tests, you have scored 91,95 and 88 points. You are ...
 Math  a group of 100 students took a quiz. Their average score was 76 points. ...
More Related Questions