In a certain brick wall, each row of bricks above the bottom row contains one less brick than the row just below it. If there are 5 rows in all and a total of 100 bricks in the wall, how many bricks does the bottom row contain ?	Pick one
A) 18  B) 16  C) 17  D) 15  E) 19

Rationale: "the bottom row has x bricks x + x - 1 + x - 2 + x - 3 + x - 4 = 100 5 x - 10 = 100 5 x = 90 x = 18 answer : a"
Answer: A