A’s mother is twice as old as A’s brother. A is 6 years younger than his brother but 4 years older than his sister. If A’s sister is 15 his mother’s age is:

A’s mother is twice as old as A’s brother. A is 6 years younger than his brother but 4 years older than his sister. If A’s sister is 15 his mother’s age is:

(a) 40

(b) 45

(c) 42

(d) 50