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 6 rows in all and a total of 135 bricks in the wall, how many bricks does the bottom row contain ?
Choose one:
A) 21	B) 20	C) 22	D) 19	E) 24
The bottom row has x bricks   x+x-1+x-2+x-3+x-4+x-5 = 135   6x-15=135   6x=120   x= 20   Answer:20
<result>B</result>
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 6 rows in all and a total of 135 bricks in the wall, how many bricks does the bottom row contain ?