The average age of a group of 9 friends is 22 years. LAVGIR is the youngest and his age is 6 years, then what happened to be the average age of the family just before LAVGIR was born?

Solution

Given average age of 9 members is 22 years.
This implies Sum of all 9 members age's = 22(9) = 198

As it is given LAVGIR is 6 years old :
Before he was born , rest of 8 members age's would be less than present by 6 years . So, we can subtract 6 years for all 9 members :
198-9(6) = 144

Therefore average = 144/8 = 18