It is given Nadia goal is to sell 100 tickets out of which she has already sold 17 tickets .
Total number of tickets = 100
Number of tickets sold =17
Number of tickets left = 100-17=83
Nadia can sell 10 tickets in a day
Number of days required to sell remaining 83 tickets if 10 tickets is sold everyday = 83÷10=8.3
Nadia will need minimum of 8+1=9 days to sell the tickets.
Option D 9 is the right answer.