Which of the following is NOT a correct way of calculating a liquidity ratio?

Liquidity Ratio $=$ Liquid Assets $\frac{?}{?}$ Short$-$term Liabilities

Current Ratio $=$ Total Current Assets $\frac{?}{?}$ Total Current Liabilities

Operating Cash Flow Ratio $=$ Current Liabilities $/$ Operating Cash Flow

Quick Ratio $=($Current Asset $-$ Inventories $-$ Prepavments$)\frac{?}{?}($urrent I iahilition