How high can pallets or crates of Stone be stacked?

What does a romen numeral with a bar on top mean? How many km make 500 mile? What is the full form of ISSN? How do you find radius when arc length is given? What is an objects average speed when an object moves over a distance of 500 meters in 25 seconds? Does a mirror reflect without light? What part of an atom exists in areas of probability? How do you write 7 15 as decimal? Do rectangles have four congruent sides? How do you find the point of tangency? How do you write 580 million in digits? What does the eighth say? How many dozens of each kind of cookies should abby and bing make so that their profit is as high as possible? Does The Bible call the angels gods? How much does 4 go into 81? What is the purpose of differential calculus? What are the coordinates of the image produced by applying the composition? What was Anne Bonny's branch in 39 clues? What is two thirds divided by one forth? Is a quart a metric unit?