Question

Three years ago, the average age of a family of five members was 17 years. After a baby is bom, the average age of the family is the same today. What is the age of the baby​

Answer 1

Answer:

So, now we know that the average age of 5 members of a family 3 years ago is 17 years. So, sum of ages of all members of family 3 years ago will be (average age)*5. Sum of ages of five members of family 3 years ago will be 17*5 = 85 years.