Do The Math Q7

An insurance company determines that N, the number of claims received in a week, is a random variable with P[N = n] = 1/2n+1, where n > 0 . The company also determines that the number of claims received in a given week is independent of the number of claims received in any other week. Determine the probability that exactly seven claims will be received during a given two week period.

  1. 1/256
  2. 1/128
  3. 7/512
  4. 1/64 Correct Answer
  5. 1/32

SOLUTION: D

Let N1 and N2 denote the number of claims during weeks one and two, respectively.

Then since N1 and N2 are independent