For 13, do 18÷45 and for 14 is 45 minutes exact

The multiples of 105 are 3,5,and 7 so none of them can come out of the square root so it cannot be simplified.
I don't know the answer but my tip would be to split the shape the way I did it, find the lengths of each side, and then find the area for each individual shape.
Then add all the areas together.
Answer:
white to grey is 13:12
Step-by-step explanation:
The grid has 25 squares, shade 12 of them grey