The ratio of clownfish to angelfish at a pet store is 5: 4 the ratio of angelfish to goldfish is 4: 3 there are 60 clownfish at the pet store .

So if there are 60 clownfish and the ratio from clownfish to angelfish is 5:4, this is the equation you are looking at:
5:4 = 60:? 
To find ? you have to do 60 divided by 5 which equals 12 and multiply it times 4 to see how many angelfish there will be if there are 60 clownfish.
12 x 4 = 48
So if there are 60 clownfish there will be 48 angelfish. The ratio is 60:48

For the next one, same thing if there are 48 angelfish, then you are looking at this equation: 
4:3 = 48:? 
Again, we solve like we did the last one. 
48 divided by 4= 12
3 x 12= 36
So, if there are 48 angelfish there will be 36 goldfish. The ratio is 48:36 
I hope this helps:)