The second cat meowed twice as frequently as the three meows per minute from the first cat, for a total of 2*3=<<2*3=6>>6 meows per minute.
The third cat meowed at one-third the frequency of the second cat, for a total of 6/3=<<6/3=2>>2 meows per minute.
Thus, combined, the three cats meow 3+6+2=<<3+6+2=11>>11 times per minute.
In five minutes, the three cats meow 5*11=<<5*11=55>>55 times.
#### 55