<prompt> Desired ratio of total cholesterolHDL should be7.5103.54.5  <response>: HDL-cholesterol level HDL level above 60 mgdl protects against hea disease. Hence HDL is good cholesterol. A level below 40 mgdl increases the risk of CAD. For every 1 mgdl drop in HDL, the risk of hea disease rises 3. If the ratio of total cholesterol HDL is more than 3.5, it is dangerous. Similarly, LDL: HDL ratio more than 2.5 is also detrimental.Ref: DM Vasudevan - Textbook of Biochemistry, 8th edition, page no: 295 