be quick please

Which of the following statements is false? O a Assume that the probability of answering any one of 10 questions correctly is 0.8. The answers are independent. Them the probability of having grade of S out of 10 is around 30% O b. None of the other statements is False Consider a random variable X which takes on values 1 or 2 such that P (X = 1) = 0.25 and P (X =2) =0.75. Then the expected value of X is equal to 1 75 Consider a random variable Y which takes on values 1 or 2 such that P (Y = 1) = 0.25 and P (Y = 2) = 0.75. Then the standard deviation of Y is around 0.433