# Questions & Answers

Contents

- The missing number in the series 9, ? , 6561, 43046721 is: 81, 25, 62, 31, 18.
- Can two events with nonzero probabilities be both independent and mutually exclusive?
- Find an equation of the plane tangent to the following surface at the given point:
- The joint density of x and y is f(x y)=c(x^2-y^2)e^{-x}. Find the conditional distribution of Y, given X=x.
- The graph of a function f is shown. Which graph is an antiderivative of f?