97. The great wall is more than 20 000 kilometers long. And about ¾ of it is considered as properly preserved. I guess you are asking about the value of ¾ which is properly preserved in the said length of the great wall. => ¾ = 0.75 Thus, the formula would be like this: => 20 000 * .75 = 15 000 Thus, the ¾ value of great wall that is preserved is equals to 15 000 kilometers long,