A and B are friends and B is 2 years younger than A. A’s father D is twice as old as A and B is twice as his sister C. The age of D and C differ by 40 years. What are the ages of ‘A’ and ‘B’?

26 & 24

B=A-2 D=2A B=2C -> C=B/2 D-C=40 --> 2A-B/2=40 -> 2A-(A-2)/2=40 -> A=26, B=26-2=24

Your father is twice the age of your younger sister, who is five year younger then you. If you happen to be 30, how old is your dad?

A is 9 years older than B who is six times as old as C. The total of the ages of A, B and C is 139 years. What is the product of A and B ages ?