Mathematics for IGCSE & O level - Proportion (Section 1 - No. 15)

If *y* is inversely proportional to *x*, which statement is true?

y = kx for some constant k.

y/x = k for some constant k.

xy = k for some constant k.

x - y = k for some constant k.

Inverse proportion implies y = k/x or xy = k, where k is a constant.