Question

. Average age of a group of 50 girls is increased by 6 months when 10 of them whose average age was 16 are replaced by 10 new girls. Find the average age of new comer.​

Answer 1

Answer:

The average of new group of girls is 151

Step-by-step explanation:

Given as :

The average age of old 50 students = A years

i.e  = 50 A

Average age of a group of 50 students was increased by 6 months when group of 10 students was replaced by a group of 10 new students

So, The average of 50 new students

=  (A +  ) years

i.e  + 3 = A +  

Or,  = A -  

i.e  = 50 ( A -  )

And The average of 10 new students

= 15

So, The average of new group

150 - (A -  ) + 150 = A +  

i.e 150 - A +  + 150 = A +  

Or, 300 +  -  = 2 A

Or, 300 +  = 2 A

Or, 300 + 2 = 2 A

i.e 2 A = 302

∴ A = 302/2

Or A = 151

Hence, The average of new group of girls is 151 Answer