Average age of a group of 30 boys is 16 years. A boy of age 19 leaves the group and a new boy joins the group. If the new average age of the group is 15.8 years, find the age of the new boy.
Average age of a group of 30 boys is 16 years. A boy of age 19 leaves the group and a new boy joins the group. If the new average age of the group is 15.8 years, find the age of the new boy.
QuestionAverage age of a group of 30 boys is 16 years. A boy of age 19 leaves the group and a new boy joins the group. If the new average age of the group is 15.8 years, find the age of the new boy.
Typemultiple_choice
Option12 yearsincorrect
Option13 yearscorrect
Option14 yearsincorrect
Option15 yearsincorrect
Solution :- Let the age of new boy = X years
Total age of 30 boys = 30*16 = 480 years
As per question, if we minus age of boy who leaves the group and then add the age of boy who joins the group the new average becomes = 15.8 years.

=15.8

480 – 19 + X = 474

X = 474 – 480 +19

X = – 6 +19

= 13 years
GkSeries Editor:
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