Father is 5 years older than mother and mother's age now is thrice the age of the daughter. The daughter is now 10 years old. What was the father's age when the daughter was born?

Here , Father = F , Mother = M and Daughter = D
According to question
Age of F = Age of M + 5,
Age of M = 3 × Age of D and Age of D = 10 years
∴ Age of M = 3 × 10 = 30 years
Therefore, father's present age = 30 + 5 = 35 years
Required answer = father's present age - 10 years = 35 – 10 = 25 years