Search SchoolNGR

Sunday, 01 March 2026
Register . Login

U is inversely proportional to the cube of V and U = 81 when V = 2. Find U when V = 3

U is inversely proportional to the cube of V and U = 81 when V = 2. Find U when V = 3
Take Free Practice Test On 2026 JAMB UTME, Post UTME, WAEC SSCE, GCE, NECO SSCE
  • A 24
  • B 27
  • C 32
  • D 36
Correct Answer: Option A
Explanation:
U \(\propto \frac{1}{V^3}\)
U = \(\frac{k}{V^3}\)
k = UV\(^3\)
k = 81 x 2\(^3\) = 81 x 8
When V = 3,
U = \(\frac{k}{V^3}\)
U = \(\frac{81 \times 8}{3^3}\)
U = \(\frac{81 \times 8}{27}\) = 24

Share question on: