I have a 10" x 3" 6" slab I need to put down will 1 yard cover all that I need or can you tell me what to do?

You're all wrong! A cubic yard of concrete is 27 cubic feet. He only needs 15 cubic feet or a little over 1/2 yard. 3 feet times 10 feet equals 30 feet @ 6 inches thick equals 15 cubic feet.