Question

A wall measures 10 m by 1.5 m by 2 m. The number of bricks of size 25 cm, 15 cm by 4 cm that are needed to make the wall is ______.

Options

• 25,000

• 20,000

• 24,000

• 15,000

Answer 1

A wall measures 10 m by 1.5 m by 2 m. The number of bricks of size 25 cm, 15 cm by 4 cm that are needed to make the wall is 20,000.

Explanation:

Step 1: Convert dimensions to the same unit

• Wall dimensions: 10 m × 1.5 m × 2 m
• Convert to cm: 1 m = 100 cm

Wall: 1000 cm × 150 cm × 200 cm

Step 2: Find the volume of the wall

V_wall = 1000 × 150 × 200 = 30,000,000 cm³

Step 3: Find the volume of one brick

Brick dimensions: 25 cm × 15 cm × 4 cm

V_brick = 25 × 15 × 4 = 1500 cm³

Step 4: Find the number of bricks

Number of bricks = `V_("wall")/V_("brick")`

= `(30,000,000)/1500`

= 20,000