Asbestos tile and other kinds of floor tiles were made in 4 foot by 8 foot sheets that were then cut or punched to the size wanted. So 9 inch tile might include an asbestos component but may do note. The same can be said for 12 inch tile and any other shapes and sizes . The only way to know for certain is to have a piece of tile analyzed by a competent analytical lab.
It seems to have been discontinued...and if you pull it up, BE CAREFUL! The majority of nine-inch floor tile contains asbestos, and so does the glue it was installed with.
1 sq foot = 144 sq inch 3 inch x 3 inch = 9 sq inch = 9/144 sq feet = 0.0625 sq feet
6 feet by 1.5 feet would be 16 9-inch tiles
There are: 8/12 times 10/12 = 5/9 square feet
One 9 inch square tile would presumably be 9in x 9in or 81in2, unless you are meaning 3in x 3in tile which is then 9in2. Regardless, the answer to your question is the total area of the floor (in square inches) divided by the total area of one tile (in square inches).
888.88
Assuming they are 16 INCH * 16 INCH tiles, the area is 16/12 * 16/12 = 16/9 = 1.77... sq feet
Divide both sides by 12 to change to feet:- 8/12 times 16/12 = 8/9 square feet
Nine in each square foot. (27 times 9 equals 243).
Most Vinyl Asbestos Tile (VAT) was out of the system by 1979 however in an effort to make sure the wholesale & retail pipeline was all clear & without creating a financial burden on the companies with inventory they were given until 1984 to clear inventory & certify that it was all gone. One other change was implemented to assure that the consumer & regulators could verify compliance. Before 1979 most VAT tiles were 9"x9" after 1979 no one was allowed to make new tile with asbestos and no 9X9's were ever produced after that date. So if you see 12X 12 or bigger tiles you can be pretty sure they are Vinyl Composite Tiles (VCT) asbestos free.
This really depends on what type of vinyl and condition of vinyl and subfloor. A really BIG consideration is if there is asbestos in tile (or if you suspect there might be). If you have 9 x 9 tiles that looks like VCT (Vinyl composite tile), there is a high likelihood that they are in fact VAT (Vinyl Asbestos tiles) in which case I would recommend leaving them since removing them can be dangerous to your health. Also, some types of older vinyl have asbestos in the adhesive. If you do not have asbestos tile, it's often better (but more costly) to rip up the vinyl. And, sometimes when you do, it causes additional damage to the subfloor which in turn can additional costs to floor prep. Alternatively, if height is not an issue, you can often add on a piece of 1/4" plywood on top, and then put the vinyl on top of that...or sometimes, you can add a couple of skim coats between layers. If they vinyl is coming up, it's generally best to remove it all (unless you think it's asbestos tile...in which case if it's coming up you may want to call an abatement company (which can be extremely expensive. However, if the VAT is coming up due to water damage, sometimes this will be covered by your homeowner's insurance.
9 caliber is 0.09 inch, smaller than any standard ammunition made. 0.09 inch = 2.286 mm. Perhaps you were thinking "What caliber is 9 mm?". 9 mm = 0.354 inch = 35.4 caliber.