Lipids are insoluble in water because lipid molecules are

Assertion $A$: Fat is stored in the body as a reserve food material.
Reason $R$: Lipid is a nutrient with a high energy value.
Which option is correct for Assertion $A$ and Reason $R$?

Phospholipids are esters of glycerol with

How many molecules of fatty acids combine with one molecule of glycerol to form a lipid molecule?

Assertion $(S)$: In the structure of lipids,one to three molecules of fatty acids are attached to one molecule of alcohol.
Reason $(R)$: Alcohol is present in the structure of lipids in the form of trihydroxy alcohol or monohydroxy alcohol.

What does a trihydroxy alcohol contain?