SOLUTION: average age of 25 students is 17 years. If we add the age of teacher also, average age increase by one year. The age of a teacher in years is?

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Question 1024248: average age of 25 students is 17 years. If we add the age of teacher also, average age increase by one year. The age of a teacher in years is?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
In words:
[ average of ages ] = [ total of ages ] / [ number of individuals ]
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Let +t+ = total of ages
Average for just the students:
+17+=+t+%2F+25+
+t+=+425+
The student's ages total +425+
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Let +x+ = the teacher's age
Add in the teacher to same formula:
+17+%2B+1+=+%28+425+%2B+x+%29+%2F+%28+25+%2B+1+%29+
+18+=+%28+425+%2B+x+%29+%2F+26+
+425+%2B+x+=+468+
+x+=+43+
The teacher is 43
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check answer:
+%28+425+%2B+43+%29+%2F+26+=+18+
+468+=+26%2A18+
+468+=+468+
OK