The volume of a wall which is 5 times as high as it is broad and 8 times as long as it is high, is 12.8 m3. The breadth of the wall is
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 40 cm
The wall is a cuboid, so volume = length × breadth × height. Writing the height and the length in terms of the breadth \(b\) leaves one unknown.
Height \(=5b\); length \(=8\times5b=40b\)
Volume \(=40b\times b\times5b=200b^3=12.8\)
The breadth: \(b^3=0.064\), so \(b=0.4\,\mathrm{m}=40\,\mathrm{cm}\)