Area of wall = Length(Height)
Area of wall = 3ft(11ft) = 33ft^2
each Brick (1/3)(1/2) = 1/6ft^2
Divide 33ft^2 total by 1/6ft^2 per brick
33/(1/6) = 33(6/1)
Answer to single layer wall will be 198 bricks to complete the walkway.
For two layer wall, multiply number of bricks obtained by 2
therefore 2(198) = 396 for second layer of wall.
Hope I answered your question!!!!
