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.
Quick Answer. The causes of leg muscle pain and weakness include various conditions, such as deep vein thrombosis, gout, various injuries and sprains, according to Mayo Clinic. Other causes of leg pain and weakness are osteoarthritis, sciatica and varicose veins. Continue Reading.