Directions: Read the Read the following information carefully and answer the related questions.
There are seven persons in a family having three generations. The family has 3 females (Riya, Priyanka and Malaika), 4 males (Prem, Varun, Kaartik and Rishi) and two couples. The difference between the age of any child and its parents is at least 20 years. For each person either both the parents are alive or none of the parents are alive.

The sum of the ages of Kaartik and Prem is the same as the sum of the ages of Priyanka and Riya. The ages of two persons in the family are the same and the ages of the remaining 5 are different. The family has three siblings and the ages (in years) of all three of them are different odd prime numbers less than 11. The sum of the squares of the ages (in years) of two of the three siblings is the same as the sum of the ages (in years) of their parents. The age of only one person in the family is a non–prime number and that person is the grandfather of Prem. No person in the family is more than 57 years old. None among Prem, Priyanka and Riya is the youngest person in the family. Riya is older than Priyanka but she is not the oldest and Varun is older than Rishi.