Question

Nikki is building a wall with bricks. Each brick is 10 inches long. The bricks are laid end-to-end, and one inch of mortar is layered between each brick.

a. Write and equation to model the number of bricks, N, Nikki needs in each layer to build a wall 10 feet long.


b. Solve the equation and state your result in words.

Answer 1

b = 11

11 bricks will be required with 10 (1 inch motar) in between the bricks.

Explanation:

Given the following :

Length of brick = 10 inches long

Between each laid brick, there is an inch of mortar layered before the next brick.

Number of bricks needed to build a wall which is 10 feets long.

Converting from feet to inch :

1 foot = 12 inches

Hence,

10 feets = (10 × 12) = 120 inches (length of wall).

Hence number of bricks needed in each layer :

Total length of b, bricks = length per brick × b = 10b

Since mortar is laid in between any two bricks, then length of mortar for b, number of bricks will be (b-1) inches

Since the total length of wall to be constructed is 120 inches ;

Then the equation required =

Sum of brick length + mortar = 120 inches

10 b + (b - 1) = 120

11b - 1 = 120

Hence,

11b = 120 + 1

11b = 121

b = 121 / 11

b = 11

Number of mortar = (b - 1) = - 11 - 1 = 10

Hence, 11 bricks will be required with 10 (1 inch motar) in between the bricks.