A sparse ruler is called optimal if it is both minimal and maximal. Since the number of distinct pairs of marks is m ( m â 1 ) / 2 {\displaystyle m(m-1)/2} , this is an upper bound on the length L {\displaystyle L} of any maximal sparse ruler with m {\displaystyle m} marks.
1 One 23/32-inch 4x8-foot plywood piece weighs approximately 67 pounds, while a piece of OSB of the same dimensions weighs approximately 78 pounds.
edit Cost of Plywood vs OSB. OSB is cheaper than plywood by about $3 to $5 per panel. For a typical 2,400 sq. ft. home, OSB is about $700 less expensive compared with plywood if used as the subfloor, sheathing, and roof decking.s OSB is cheaper than plywood and has the strength and durability of plywood it is becoming more widely used than plywood. OSB was introduced in the 1970s and steadily gained market share from plywood, surpassing plywood in production in 2000. Today OSB has 70-75% market share and plywood has about 25% share.