What do the marks star 778 AR mean on gold?

If a toy car has weight added to it and then sent down a ramp will it go slower or faster? What is 1-⅔? What are synonyms of difficult? What is the base of a cylinder called? What is the lowest point on a graph in the domain of the function called? what is 3426 rounded to the nearest 1000? How many places do you move the decimal to the left to make it science notation 6000000000000? What is July 29 1967 in roman numerals? What is the dimension of work and pressure? How much does 1 cusec mean? How many Edges and vertices and Faces does a trapezium prism? If a jar is filled with only dimes and quarters and there are 57 coins and the value is 19.00 how many quarters are there? What is the smallest prime? How do you convert 7 feet by 9 feet into square meters? Which distribution function has equal mean and variance? What jobs use statistics? Is every integer a natural? Let K be an extension of the field Q of rational numbers? Definition of similar terms? Is a cubic inch equal to 1 inch of volume?