What is valitility?

How to round 30.9199? What part of a yard is one inch? What is the volume of Egypt's great pyramid in metres squared? What is the product in 3.82 x .01? How do you find the greatest common factor of 12 and 15 using prime factorization? What does it mean when the terms in a ratio are equal? What discovery did the Chinese make more than 1000 years before the Westerners? What is twelve thousand twelve hundred twelve in simplest form? What is the number 1 better site? What are the problems of nepad? What is 4.3billion in scientific notation? It is greater than 30 and less than 40 if you add them the sum is 10 what is the number word? How many fence posts would you need if you put a post every 10 feet around the perimeter of a square garden that is 50 feet on each side? What is the standard speed in miles per hour of the light if a travels at 15000 kilometers per second? What is 87 plus 56 times two? Which is greater 10000mg or 13g? What is regular smocking? What is 8 over 13 as a decimal? How many yards must you be away fromn your opponents in hockey for any free hits or restarts? A quadralateral with exactly one pair of parallel sides?