3 Years ago, the average age of a family of 5 members was 18 years. A baby having been born, the average age of the family is the same today. The present age of the baby is Choose the correct answer:
A) 1 year.  B) 1.5 Years.  C) 2 Years.  D) 3 Years.  E) 4 Years.
We're told that 3 YEARS AGO, the average age of a family of 5 members was 17 years.   This means that the SUM of their ages was (5)(18) = 90 years.   A baby was born (meaning that there are now 6 family members). We're told that the PRESENT average age of the family members is the SAME.   This means that the sum of the ages is (6)(17) = 102 years.   We're asked for the PRESENT age of the baby.   Since each of the original 5 family members has aged 3 years since the initial average was calculated, the sum of their PRESENT ages is...   90 + (5)(3) = 108.   3 Years.
<result>D</result>
3 Years ago, the average age of a family of 5 members was 18 years. A baby having been born, the average age of the family is the same today. The present age of the baby is