SOLUTION: There are 24 students in a class. A student whose age is 18 years left the class. And his place is filled with another student. The average of the class was nearly lowered by 1 mon

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Question 1110115: There are 24 students in a class. A student whose age is 18 years left the class. And his place is filled with another student. The average of the class was nearly lowered by 1 month. The age of new student is?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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There are 24 students in a class.
A student whose age is 18 years left the class.
And his place is filled with another student.
The average of the class was nearly lowered by 1 month.
The age of new student is?
:
Let t = total of 23 student in months
then
%28t%2B12%2818%29%29%2F24 = the original average of the students in months
x = age of the new student in months
Original av - new student av = 1 month
%28t%2B216%29%2F24 - %28t%2Bx%29%2F24 = 1
multiply by 24, cancel the denominator
t + 216 - (t + x) = 24
t + 216 - t - x = 24
T's drop out
216 - x = 24
216 - 24 = x
192 = x
x = 192 months is the age of the new student therefore
192/12 = 16 yrs is the age of the new student in years.