2560000 sequences of answers are possible.
Explanation
Total number of questions = 10
First 4 questions have 5 choices each and remaining (10-4)= 6 questions have 4 choices each.
So, the possible sequences of answers for first 4 questions [tex]= 5^4 = 625[/tex]
and the possible sequences of answers for remaining 6 questions [tex]= 4^6=4096[/tex]
Thus, the total possible number of sequences of answers = (625 × 4096) = 2560000
