Technically, 2.6388888888888 etc. but 3. I'm assuming the brick is 12x12 feet here as that is the only unit you have mentioned...
Assuming the 12x12 bricks are 12 feet on each side, those are 144 square feet. The patio itself is 76 square feet. Unless you made a typo, not even one of those bricks is going to fit on the patio; you end up with about 0.5278 bricks.
Each brick has an area of 1ft x 1ft ie 1 sq foot. So you would need 308 bricks.
A 12 x 12 inch brick is 1 square foot. A 20 x 20 (foot) patio is 400 square feet, so you would need 400 bricks.. this assumes you are butting the bricks fairly tight, not leaving large seperations between them, etc...
A 12" x 12" brick covers an area of one square foot. Assuming your patio is 396 square feet, then you would need 396 bricks. However, you will almost certainly have to cut some bricks to fit them into whatever shape your approximately 20' x 20' patio will be, so you should figure on needing a few more. The rule of thumb is to order what you need plus 10% extra, but make sure you can return the unused bricks. Area covered by 12x12 inch brick is 144 square inches. That is 1 square foot. Total area of the patio is 396 square foot. Number of bricks required = 396/1 = 396 bricks. Source: www.icoachmath.com That gives you the extra ten percent you'll need to compensate for cutting, breakage, etc.
About 14 bricks should do it.
115 should do it!
A lot !!