Simplify 586645 * 9999  Choose one.
A) 5865863355 B) 5665863355 C) 4865863355 D) 4665863355 E) none of these

Rationale: explanation : although it is a simple question , but the trick is to save time in solving this . rather than multiplying it we can do as follows : 586645 * ( 10000 - 1 ) = 5866450000 - 586645 = 5865863355 option a
Answer: A