A one-foot stick is marked in 1/4 and 1/5 portion. How many total markings will there be, including the end points?	Choose the correct choice from the following:  A) 18  B) 16  C) 13  D) 9  E) 11

Rationale: lcm of 20 = 20 1 / 4 marking are ( table of 5 ) 0 . . . . . . 5 . . . . . . 10 . . . . . 15 . . . . . . 20 ( total = 5 ) 1 / 5 marking are ( table of 4 ) 0 . . . . . . . 4 . . . . . . 8 . . . . . . 12 . . . . . . . . 16 . . . . . . 20 ( total = 6 ) overlapping markings are 0 . . . . . . . . 20 ( total = 2 ) total markings = 5 + 6 - 2 = 9 answer = d
Answer: D