If a company produces phones and earns $32 million in sales but pays $24 million for the items sold, then the company's gross profit margin would be ($32M - $24M) / $32M = 25 percent.
Burning legs can result from a number of causes, including damage to nerves in the legs from exposure to extreme heat or cold or to toxic substances. Burning legs might also result from a circulation problem that impairs blood flow to the legs, a leg injury, or intense exercise.
There are many medical conditions that can cause leg pain. 1  Fibromyalgia sufferers frequently experience restless leg syndrome and painful lower leg cramps.  Leg pain can also be associated with autoimmune disorders such as multiple sclerosis and rheumatoid arthritis. Thyroid disease can also cause pain in the legs.