project 8 less marks in ABC call volume

sir i have presented my project 8 with the appropriate analysis but the review said that the question 3 and 4 are wrong . i have used the erlang method and unitary method which is used to calculate agent total head. sir my answer may vary due to assumption but the method i used is appropriate. if their is something wrong please enlighten me with the process. and i want to also explain that my analysis of manpower plan is contributed for month and determined values are considered as approximately as i have told in my video.please, kindly recheck my project considering these facts and provide a satisfactory results.