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 wall is 5 times as high as it is broad, so h = 5b
The wall is 8 times as long as it is high, so l = 8h
volume of the wall is 12.8 m³ = 12800000 cm³ ( given )
Volume = Length × Height × Breadth
12800000 = l × h × b
Now, substitute the expressions for "l" and "h" from the relationships above:
12800000 = (8h) × 5b × b
12800000 = (8 × 5b) × 5b × b
12800000 = 200 × b³
64000 = b³
b = 40 cm