A girl went to school and the teacher asked her "how old are you? she replied l don't, but l know that l'm half my mother's age. The teacher asked "how old is your mother? she said l don't know but l know that my dad is 5years older than my mother . The teacher asked "how old is your dad then? she said l don't know but l know that if we add our ages, the answer is 10% of a thousand. Now, how how old is the girl, her mum and dad?