Question

the mean age of 25 students In a class is 12 if the teachers age is included the mean age increases by 1 then find the teachers age in years

Answer 1

Given that the mean of 25 students = 12.

Total age of 25 students = 25 * 12

                                          = 300.

Given that the teacher's age is included, then the mean becomes 12 + 1 = 13.

Now, Total age of 25 students and teacher = 13 * 26

                                                                          = 338.


Therefore the average of teacher = 338 - 300

                                                         = 38 years.



Hope this helps!

Answer 2

Given that mean of 25 students is 12

which means that the sum of their ages will be
25 ×12=300

if one teacher is is included then total people will be 25+1=26

and

mean is increased by 1 means the new mean will be 12+1=13

then new sum will be 26*16=338

=> teacher's age will be 338-300=38 years


HOPE IT HELPS YOU.
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