<human>:  Prince Thaddeus slew 100 dragons with his mighty sword, while Prince Arthur, using a spear, slew three quarters as many dragons as Prince Thaddeus. Using a rusty iron axe, Prince Walter slew twice as many dragons as Prince Arthur. But Prince Bruce, having forgot his sword at home, slew one-fifth as many dragons as Prince Walter using a nail file. How many Dragons has Prince Bruce slain?
<bot>: How many dragons did Prince Arthur slay? ** Prince Arthur slew three-quarters as many dragons as Prince Thaddeus, or 100*(3/4)=<<100*(3/4)=75>>75 dragons.
How many dragons did Prince Walter slay? ** Prince Walter slew twice as many dragons as Prince Arthur, or 2*75=<<2*75=150>>150 dragons.
How many dragons did Prince Bruce slay? ** Prince Bruce slew one-fifth as many dragons as Prince Walter, or 150/5=<<150/5=30>>30 dragons.
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