You have 33 photos
You need to separate the photos in two groups for a ratio of 4:7
So what you do is add both numbers of the ratio

Then divide the 33 photos by 11

÷

So that means that each number in the ratio is equivalent to 3 photos
Now multiply each ratio by 3

and

So the ratio of the photos are 12 to 21 or 12:21
Answer: ratio is 12 to 21 or can be written as 12:21