Answer:
25 times
Explanation:
If the magazine(we are assuming it's a magazine as we are not told) publishes 5 out of 12 issues of a photo of main dish each year then out of every 12 issues each year it only publishes 5 photos of main dish
The proportion is therefore 5/12
In five years there will be 12*5=60 issues of a photo of a main dish and 5*5=25 published photos of a main dish.
Therefore a photo of a main dish will be on the cover 25 times out of 60 issues in five years
To check if we are correct, we check the proportion to see if it still evaluates to 5/12
25/60= 5/12 when reduced to lowest terms