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.
Many causes of leg pain are obvious, such as injury after an accident. Leg pain can have less obvious causes, such as peripheral artery disease. Repetitive, excessive sports, especially in the form on running, can lead to trauma that creates leg pain - E.G: shin splints and stress fractures.