Answer: 9 tilapia
Step-by-step explanation:
The ratio of 6:20 for tilapia to catfish means that for every six tilapia, there are 20 catfish in the pond.
If there are 30 catfish, use direct proportion to find out the number of tilapia:
6 : 20
x : 30
Cross multiply:
20x = 180
x = 180 / 20
x = 9 tilapia