Question

The average age of 25 persons is 30 years. 5 persons are included, then the average age becomes 32 years. Find the average age of new persons.

Answer 1

Sum of ages of 25 persons
= 25 x 30 = 750 years 

Sum of ages of 30 persons
= 30 x 32 = 960 years

∴ Ages of 5 persons
   = 960 – 750 = 210 years

∴ Required average = 210 / 5 = 42 years.

Hence, average age of new persons is 42 years.