Statistic problem!!????

in a test of ESP ( extrasensory perception) the experimenter looks at cards hat are hidden from the subject. Each card contains a star, a circle, a wavy line, or a square. An experimenter looks at each of 100 cards in turn, and the subject tries to read the experimenter's mind adn name the shape on each card. What is the probability that the subject gets more than 30 correct if the subject does not have ESP and is just guessing?