As you know, water evaporates in heat, and tropical places are usually very hot! Tropical implies "ocean" so, when an ocean evaporates it leaves a sandy ocean floor, which is a desert, but there are lake sized "puddles" of salt water left over, which is why there is a big salt water lake in the middle of Utah.
300N - 50N = 250N
250N to the right
It was used as a secret code among the slaves.
