Question

1. Out of 180 business executives, 75 read Fortune, 70 read Time, 55 read Money, 45 read exactly two of the three magazines, and 35 read none of the three magazines. How many read all three magazines? (Hint: draw a Venn Diagram, denote the number of elements in each basic region by x, y, z, etc., and find the number of those who read all three magazines from appropriate equation(s)/principle(s).)

2. A student estimates that the probability of getting any grade below “A” in history is 0.3, the probability of getting any grade below “A” in psychology is 0.2, whereas the probability of getting “A” in history or psychology is 0.9. What is the probability that the student gets an “A” in both history and psychology?

3. Ten gadgets are tested. The probability that any given gadget is detective is 0.1. What is the probability that exactly one of the 10 gadgets is defective? What is the probability that at least one of the 10 gadgets is defective?

4. In a lottery, a player buys a ticket and selects 6 numbers from the numbers 1 through 49. What is the probability of selecting exactly three of the six numbers drawn in the lottery?

5. Two players each toss a coin three times. What is the probability that they get the same number of tails?

Answer 1