Test Index

Volumes Practice Test 4

Question : 12 of 16

Marks: +1, -0

\frac{1}{7}

Solution:

Concept:

Divide the wall volume by the effective volume of one brick including mortar.

Explanation:

Convert all dimensions to centimetres.

Wall dimensions are

800\ \mathrm{cm}

360\ \mathrm{cm}

, and

80\ \mathrm{cm}

Wall volume:

V_{\text{wall}} = 800 \times 360 \times 80 = 23040000\ \mathrm{cm}^3

Original volume of one brick:

V_{\text{brick}} = 20 \times 12 \times 5.6 = 1344\ \mathrm{cm}^3

Mortar increases each brick volume by

\frac{1}{7}

Increase:

\frac{1}{7} \times 1344 = 192\ \mathrm{cm}^3

Effective volume of one brick:

V_{\text{effective}} = 1344 + 192 = 1536\ \mathrm{cm}^3

Number of bricks:

N = \frac{23040000}{1536} = 15000

Answer:

15000

bricks are required, so option A is correct.

Go to Question:

Prev Question

Next Question