A light fixture contains 2 light bulbs. The lifetime Xi of each bulb is exponentially distributed with a mean of 200 hours, i= 1,2,3. Suppose bulb lifetimes are independent from one another. Let T equal the time until a bulb in the fixture needs replacement.

a) What is the paramater Lamda of the exponential distribution?

b) What is the probability that X1 > 100 hours?

c) What is the expected value of X1?

d) What is the probability P(X1 > 100 and X2 > 100 and X3 > 100)?

e) What is the probability P(T > 100)?

f) If t is any positive number fine P(T > t)?

g) If t is any posivtive number fine P(T ? t)?