2015 · Q9
The value of 1/1× 4+1/4× 7+1/7× 10++1/16× 19 is
Elementary MathematicsNumber System
- A5/19
- B6/19
- C8/19
- D9/19
Explanation
Each term 1/((3k+1)(3k+4)) = (1/3)[1/(3k+1) - 1/(3k+4)]. Telescoping over the 6 terms gives (1/3)(1 - 1/19) = 6/19. Hence option (b).