Now when the man is 50 years old and his brother is 7 years older than him ∴ the age of brother will be 57 years Now as the sister is 12 years younger than his brother ∴ the age of sister will be (57 – 12) = 45 years So the present age of man, brother and sister is 50, 57 and 45 respectively ∴ When his sister was 20 years old i.e. (45 - 20) 25 years ago the men’s age will be (50 – 25) = 25 years