Three years back the average age of a family of 6 members was 19 years. A baby having being born, the average of the family remains the same. Then the age of the baby (in years) is

1
l1/2
2
3

The correct answer is (c) 2.

Three years ago, the total age of the family was 6 x 19 = 114 years.
The total age of the family now is 114 + 3 x 6 = 132 years.
The total age of the family including the baby is 132 + 2 = 134 years.
The baby is 2 years old.

Option (a) is incorrect because 1 year is too young for a baby.
Option (b) is incorrect because 11/2 years is not an integer.
Option (d) is incorrect because 3 years is too old for a baby.