The average age of 4 member of a family is 25 yr. If head of the family is included in this group then average age increase by 20%. Find out the age of the head.
Correct Answer: 50 yr
Explanation:
Total age of 4 member = 25 x 4 = 100 yr
Total age of 5 members including the head
= 5 x (25 + 25 x 20/100)
= 5 x 30 = 150 yr
∴ Age of the head = 150 - 100 = 50 yr
