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.
Diabetes and alcohol abuse are by far the most common causes of neuropathy in the legs. Besides neuropathy, infections and inflammation of the feet can also cause a burning sensation. The most common of these is athlete's foot, an infection of the skin caused by fungus. Peripheral artery disease (PAD) also commonly causes burning feet.