None of them are equivalent.
Let 's' be the allowed speed.
If the maximum speed is 70 and the minimum is 40, we know 's' is between these two values inclusively, i.e. 40 ≤ s ≤ 70
*Remember for inequality symbols, whether strict or inclusive, the term on narrow side is "less than" the term on the broad side
The line CD is the median of thre trapezoid, therefore its measures is shown below:
You must sum the largest base and the shortest base and divide both of them by 2, as following:
CD=(4.5+2.5)/2
CD=7/2
CD=3.5
Therefore, as you can see, the measure of the line CD is 3.5
The answer is: 3.5
I think the answer would be 64/4 or 64/ 16