What each letter stand for?

How old would a sixteenth student have to be for the mean age of the class to be 21.0 years? What percentage of people score between 85 and 115 on IQ tests? Is it possible for to numbers to be relatively prime? Why are yards called yards? What does the letter x mean in algebra? What Conversion of 001100 binary number into decimalçbvc? What does the french word suare mean? 8 numbers between 31 and 41 that are composite numbers? What is twelve ninths in simplest form? How many a minutes a day does daylight move? What is nomex 3? A butterfly in kilograms or grams? How can knowing the shoe size of someone tell you what their height is? How can patterns be used to determine products of a number and a power of ten? Is a figure with a scale factor of 1 congruent or similar? Is true that all polygons can be constructed entirely from the repetition of a single length of line segment? What is 3.5 percent of 360.000 thousand pounds? Later cicivilations developed basic algebra and geometry by building on the number system first created by what civilizaion? Find the area of a parallelogram with a base of 420 centimeters and a height of 156 centimeters? How do you convert 210 cm to km?