A question paper had ten questions. Each question could only be answered as True (T) or False (F). Each candidate answered all the questions. Yet, no two candidates wrote the answers in an identical sequence. How many different sequences of answers are possible?[UPSC 2010 (CS-P)]
a) 20
b) 40
c) 512
d) 1024

• 1024 ways.
  each question can be answered 2 ways then 10 questions can be answered in 2^10 ways=1024
• 9 years agoHelpfull: Yes(0) No(1)