Math Problem Statement

Joe has a rectangular block of wood with measurements: height = 900 mm, length = 1.8 m, and width = 36 cm. Joe wants to cut the block into cubes with side lengths of 18 cm. How many cubes can Joe cut from the block? Options: (A) 10, (B) 20, (C) 100, (D) 1000.

Solution

We are given a rectangular block of wood with the dimensions as follows:

  • Height = 900 mm = 90 cm (since 1 mm = 0.1 cm)
  • Length = 1.8 m = 180 cm (since 1 m = 100 cm)
  • Width = 36 cm

Joe wants to cut this block into cubes, each with side lengths of 18 cm.

Step 1: Calculate the volume of the rectangular block.

The volume VblockV_{\text{block}} of a rectangular block is given by: Vblock=Length×Width×HeightV_{\text{block}} = \text{Length} \times \text{Width} \times \text{Height} Substituting the given dimensions (all in cm): Vblock=180cm×36cm×90cm=583200cm3V_{\text{block}} = 180 \, \text{cm} \times 36 \, \text{cm} \times 90 \, \text{cm} = 583200 \, \text{cm}^3

Step 2: Calculate the volume of one cube.

The volume VcubeV_{\text{cube}} of a cube is given by: Vcube=side length3V_{\text{cube}} = \text{side length}^3 Substituting the side length of 18 cm: Vcube=18cm×18cm×18cm=5832cm3V_{\text{cube}} = 18 \, \text{cm} \times 18 \, \text{cm} \times 18 \, \text{cm} = 5832 \, \text{cm}^3

Step 3: Determine how many cubes fit into the block.

To find how many cubes Joe can cut from the block, divide the volume of the block by the volume of one cube: Number of cubes=VblockVcube=583200cm35832cm3=100\text{Number of cubes} = \frac{V_{\text{block}}}{V_{\text{cube}}} = \frac{583200 \, \text{cm}^3}{5832 \, \text{cm}^3} = 100

Thus, Joe can cut 100 cubes from the block.

The correct answer is (C) 100.


Would you like any further details or explanations on any part of the solution?

Here are 5 related questions to deepen understanding:

  1. What is the formula for the volume of a cube?
  2. How do you convert between different units of measurement, such as meters to centimeters?
  3. Can Joe cut cubes with a side length of 15 cm instead? How many would fit?
  4. What happens if the dimensions of the block change? How does this affect the number of cubes?
  5. What other shapes could Joe cut from the block, and how would you calculate those?

Tip: Always make sure all units are consistent before performing calculations to avoid errors.

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Math Problem Analysis

Mathematical Concepts

Geometry
Volume Calculation
Unit Conversion

Formulas

Volume of a rectangular prism: V = length × width × height
Volume of a cube: V = side^3
Unit conversions (e.g., mm to cm, m to cm)

Theorems

Basic volume calculation formulas for 3D shapes

Suitable Grade Level

Grades 6-8