In 10 years, A will be twice as old as B was 10 years ago. If A is now 9 years older than B, the present age of B is  Choices:
A) 27	B) 66	C) 39	D) 28	E) 21
Let B's present age = x years. Then, A's present age = (x + 9) years.   (x + 9) + 10 = 2(x - 10)   =&gt; x + 19 = 2x - 20   =&gt; x =39.   Answer: 39
<result>C</result>
In 10 years, A will be twice as old as B was 10 years ago. If A is now 9 years older than B, the present age of B is