The ratio of red fish to blue fish is 1:5
That means that for every one red fish you have, there are 5 blue fish. In this scenario, there are 15 blue fish.
What can you multiply 5 by to equal 15?
The answer is 3. Multiply each side of the ratio by 3
1x3=3 and 5x3=15
The new ratio is 3:15, meaning if there are 15 blue fish, there are 3 red ones
I hope that makes sense!
