Mathematics for IGCSE & O level - Proportion (Section 1 - No. 44)
If *a* is inversely proportional to the cube of *b*, and *a* = 2 when *b* = 2, find *a* when *b* = 4.
1/8
1/4
1/2
1
解释
a = k/b^3; 2=k/2^3=k/8; k=16. a=16/b^3. When b=4, a=16/4^3=16/64 = 1/4