math problem?
A grid has lines at 90-degree angles. There are 12 lines in one direction and 9 lines in the other
direction. Lines that are parallel are 11 inches apart. What is the least number of 12-inch by 12-inch floor
tiles needed to cover all of the line intersections on the grid? The tiles do not have to touch each other.
You must keep the tiles intact-do not break or cut them.
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The easiest thing is always to draw a picture. You have 12 lines that are 11 inches apart. That means one edge of the area is 10 feet 1 inch long. The other edge of the room has 9 lines spaced 11 feet apart, so it is 8 feet by 3 inches long. That means that the total area is 10' 1" x 8' 3"= 83.1875 sq ft. You might be tempted to say that you can fit 83 square tiles, but remember, you're not allowed to cut! So, consider the excess 1" on one side and 3" on the other to be useless space. The area is now an even 8' by 10' which means you can put an even 80 tiles without cutting anything.
8
Each tile can cover 4 intersections
6 X 5 = 30