What is 9x9 is 81 because if you count by 9 times the 9 is 81

Asquare parking lot has 6,400 square meters what is the length in meters

What is the order of these fractions from least to greatest 2/3 7/10 5/8 65/100

The distribution of the amount of money spent by students for textbooks in a semester is approximately normal in shape with a mean of $235 and a standard deviation of $20. according to the standard deviation rule, how much did almost all (99.7%) of the students spend on textbooks in a semester?