In 20 years, A will be twice as old as B was 20 years ago. If A is now 10 years older than B, the present age of B is?
Choose the correct choice from the following:	A) 35 yrs	B) 40 yrs	C) 50 yrs	D) 60 yrs	E) 70 yrs

Rationale: "let b ' s present age = x years then a ' s present age = x + 10 years x + 10 + 20 = 2 ( x - 20 ) x + 30 = 2 x - 40 x = 70 years answer is e"
Answer: E