If X is invested in a bank at a rate of simple interest of y% p.a. for two years, then the interest earned is 400. if X is invested at y% p.a., for two years when the interest is compounded annually, the interest is 410. What is the value of X?	Choose the correct choice:
A) 8000  B) 6000  C) 5000  D) 4000  E) 3000

Rationale: "simple way to solve this question is to use options . from si , we know that x * y = 20,000 . now , put the value of x = 4000 , we will have y = 5 % to calculate ci , now , we know 1 st year amount = 4000 + 5 % of 4000 = 4200 . 2 nd year , amount = 4200 + 5 % of 4200 = 4410 . we can see after 2 years interest = 4410 - 4000 = 410 . hence , it satisfies the question . hence d is the correct answer"
Answer: D