Could you please inform me on how much it would cost to put concrete on a 36 ft. by 78 ft. piece of land, and 40 ft. by 80 ft. piece of land? You may use whatever type of concrete you like, just make it as least expensive as possible.
Your information is very helpful. Remember, concrete exists in three dimensions, width, length, and depth. I am going to answer your question as if you want the concrete to be unreinforced and six inches deep.
The area described as 36' by 78 feet will consume 52 cubic yards of concrete at an average cost of $80.00 per cubic yard. The multiplication of 52 yards times $80.00 is $4160.00 purchase. Debra, there are charges by the hour if the truck is delayed at the job site longer than normal.
The area described as 40' by 80' will consume 59 cubic yards at an average cost of $80.00 per cubic yard. The multiplication of 59 cubic yards times $80.00 is $4720.00 purchase. Again, assuming a 6" thick slab of concrete.
There are less expensive concretes, but there is no such thing as a "good" and "cheap" concrete. You'll always trade off something good for a reduction in cost.