Recent content by d.tzoneva

  1. D

    Tossing coins

    A player tosses two coins, betting 50 cent. He wins 20 cent for each fallen head. What is the expected winnings in a single toss? What should be the amount of winnings in order the game to be fair (not possible tendency for the player to win or lose)?
  2. D

    Probability students pass an exam

    Two groups, A and B wrote an exam. There are 60 students in group A and 70 students in group B. The probability of A students’ pass is 0.3 and the probability of B students' pass is 0.5. What is the expected number of students who will take the exam? What is the probability that only one student...