) ALOHA. Assume for simplicity that each transmitted packet in a slotted Aloha system is successful with some fixed probability p. New packets are assumed to arrive at the beginning of a slot and are transmitted immediately. If a packet is unsuccessful, it is retransmitted with probability qr in each successive slot until successfully received. Find the expected delay T from the arrival of the packet until the completion of its successful transmission.

1. the program must provide following functions to extract some statistics. note that the data_list parameter specified in these functions may be the same for all functions or different for different functions—that is your choice. a skeleton file is provided on mirmir. a) open_file()prompts the user to enter a year number for the data file. the program will check whether the year is between 1990 and 2015 (both inclusive). if year number is valid, the program will try to open data file with file name ‘year.txt’, where is the year. appropriate error message should be shown if the data file cannot be opened or if the year number is invalid. this function will loop until it receives proper input and successfully opens the file. it returns a file pointer and year. i. hint: use string concatenation to construct the file name b) read_file(fp)has one parameter, a file pointer read. this function returns a list of your choosing containing data you need for other parts of this project. c) find_average(data_list) takes a list of data (of some organization of your choosing) and returns the average salary. the function does not print anything. hints: i. this is not the average of the last column of data. it is not mathematically valid to find an average by finding the average of averages—for example, in this case there are many more in the lowest category than in the highest category. ii. how many wage earners are considered in finding the average (denominator)

The head restraint should be adjusted so that it reaches a.the top of your ears b.the base of your skull c.the top of the head

Acompany is hiring professionals for web designing. the firm is small with few resources. they want employees who possess problem-solving skills and can independently carry out responsibilities. which kind of employee should they select?