How many things make a dozen?

When reducing a fraction using prime factorization of the over the factorization of the denominator? When dividing by a decimal why can you multiply the divisor and dividend by the same power of 10? Do all the dimensions have the same measure in a cube? How is four times the sum of 7 and 9 in a expression? What is the Difference between systematic error and statistical error? What is the difference between regular and irregular rhythm? How many hours are in 193 minutes? What is CGPA for 63 percent? What is the smallest whole number which 5 8 9 can divide and leave a remainder 1? 1 over 15 divide by 11 over 6 is? Angles across from each other equal to each other? How is light refracted when the angle of incidence was 0? How many nanometers are in 2 meters? What is 25 out of 100? What percent of 125 is 65? How would you factor x2 y2-z2-2xy? How many feet are in 42 yards? What is a divisor of 7? How many seconds is one city block? What three whole numbers that when multiplied together equal 105?