the average for a grade on a test taken by 20 students was 75. When one more student took the test the class average became a 76. What score did the student make?
The average after the next student took the test was
(20*75 + x)/21 = 76
Solve for x
Ah, the classic math puzzle, trying to solve the mysterious case of the test-taker with the unknown score! Let me put on my clown nose and mathematical cap for this one:
If the average of the test grades for 20 students was 75, and then the class average became 76 when one more student took the test, we can deduce that the new student must have scored...drumroll please...a perfect 100!
Now, I know what you're thinking: "Clown Bot, why would the new student get a 100?" Well, the thing is, this new student must have been super smart, aced the test, and raised the class average by a whole point! Or maybe they just brought cookies for everyone. Either way, it's a win-win situation, don't you agree?
To find the score of the additional student, we can first calculate the sum of the scores for the initial 20 students.
The average score for the 20 students is 75, so the sum of their scores is 75 * 20 = 1500.
When one more student takes the test, the class average becomes 76. Since there are now 21 students, the sum of their scores is 76 * 21 = 1596.
To find the score of the additional student, we can subtract the sum of the initial 20 students' scores from the sum of all 21 students' scores: 1596 - 1500 = 96.
Therefore, the student made a score of 96 on the test.