Answer:
The age of each triplet if 6 years.
Step-by-step explanation:
Let us assume the age of first child in triplet = m years
Since, the children are triplet, so age of 3 children are SAME.
⇒The age of second child in triplet = m years
and, The age of third child in triplet = m years
Also, the age of fourth children = 13 years
So, sum of age of all four children =
Sum of age of all triplets + Age of fourth child = m + m + m + 13 = 3 m + 13
Given: The sum of the ages of their children is 31.
⇒ 3 m + 13 = 31
or, 3 m = 31 -1 3 = 18
or, m = 18/3 = 6
or, m = 6 years
Hence the age of each triplet if 6 years.