<PRE><B>Question 1102635</B>
&lt;br&gt;
The average of the 6 students is 78; the total of their scores is 78*6 = 468.&lt;br&gt;
After the 7th student joins, the average of the 7 students is 80; the total of their scores is 80*7 = 560.&lt;br&gt;
The score of the 7th student is the difference between the two totals: 560-468 = 92.&lt;br&gt;&lt;br&gt;
And here is what I think is an easier way to get to the answer to a problem like this....&lt;br&gt;
3 easy calculations are required, as shown below; an explanation of each calculation is given in parentheses.&lt;br&gt;
80 - 78 = 2  (The difference between the desired average and the current average is 2)&lt;br&gt;
2*6 = 12  (6 students are each 2 points short of the desired average; the total number of points below the desired average is 12)&lt;br&gt;
80+12 = 92  (To balance out the 12 points below average of the current 6 students, the score of the 7th student must be 12 points above the desired average)
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