PLEASE HELP AND EXPLAIN (100 POINTS AND BRAINLIEST)

As President of Spirit Club, Hassan organized a "Day of Decades" fundraiser where students could pay a fixed amount to dress up as their favorite decade. Of the 13 students who participated, 10 of them dressed up as the '50s. If Hassan randomly chose 9 of the participants to take pictures of for the yearbook, what is the probability that all of them dressed up as the '50s? Write your answer as a decimal rounded to four decimal places.​