I'm not quite sure how you got your answer, but the answer to c is 57 tiles.
First we can find the area of a singular tile by multiplying 12 and 12 together to get 144 in².
Then we find the area of the kitchen floor by splitting it into two rectangles, finding those areas, and adding them. This gives us (108 × 60) + (48 × 36) = 6,480 + 1,728 = 8,208 in².
Then to find how many tiles fit, we need to divide the total area, 8,208 in², by the area of a singular tile, 144 in², which results in 57 tiles.
I hope this helps!
