randomly selected student is a sophomore, what is the probability that he/she is left-handed? Q3. A store sells 2 different brands of DVD players. Of its DVD player sales, 60% are brand A (less expensive) and 40% are brand B. Each manufacturer offers a 1-yr warranty on parts and labor. It is known that 25% of brand A's DVD players require warranty repair work, whereas 10% for brand B. What is the probability that a randomly selected purchaser has bought a brand A DVD player that will need repair while under warranty