multi table tournament bankroll?

[1Big_Out 0]

Everyone always says the same thing about cash game bankrolls, they should be about 200, to 300 times the big bet. What about a tournament bankroll? I mean anytime you enter a tournament the odds are stacked against you to cash. Would it depend on the number of times you cash? The number of top 3 finishes you get? My main question would be is 100 buyins enough? Say I played $10+1 buy in tournaments, with 1,100 would it still be possible to go broke in the long run? Should I have more or less buy ins? Also would it depend on the number of entrants to these tournaments?