SOLUTION: The average age of a class of 30 students is 12 years. The average age of 5 students is 10 years. The average age of another group of 5 students is 14 years. What will be the avera

Algebra ->  Average -> SOLUTION: The average age of a class of 30 students is 12 years. The average age of 5 students is 10 years. The average age of another group of 5 students is 14 years. What will be the avera      Log On


   

Question 758125: The average age of a class of 30 students is 12 years. The average age of 5 students is 10 years. The average age of another group of 5 students is 14 years. What will be the average of remaining students of the class?
Pls give answer with detail calculations.
Pls examplify the same.
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
the definition of average is:
( total value of +n+ items ) / n+ = average value of +n+ items
given:
( sum of ages ) / 30 = 12
Sum of ages = 360
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5 of the 30 students average 10 yrs old
( sum of ages of this group ) / 5 = 10
sum of ages of this group = 50
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another group of 5 of the 30 students
average 14 yrs old
( sum of ages of this group ) / 5 = 14
sum of ages of this group = 70
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There are 30 - ( 5 + 5 ) = 20
students remaining
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For the remaining students:
+%28+360+-+%28+50+%2B+70+%29+%29+%2F+20+
+%28+360+-+120+%29+%2F+20+
+240+%2F+20+=+12+
The average age of remaining students is 12 yrs old