InterviewBit Problems   REC_CMPL3 : Unsolved

About the REC_CMPL3 : Unsolved category (1)
Dynamic programming 101 (1)
Didnt understand how memo element assignment alters the number of times its called (3)
Someone explain the last part (2)
I am not understanding why it is not exponential (8)
Didn't get the logic (1)
Can anyone explain what could be the value of memo[101][101] (2)
The memo array does need a description to solve the problem? (1)