The IP block of an organization starts with 157.123.10.d/x. However x, and d are unknown. a. If the organization needs at most 180 IP addresses what would be the value of x, and d. Show all your calculations. b. Based on your answer for a, if the organization needs 4 subnets of having IP addresses of 100, 40, 20, and 5 respectively what would the information of subnets in the form of a.b.c.d/x. Show all your calculations