Answer:

Step-by-step explanation:
The sum is the result obtained from adding two or more values together.
The sum of <em>s</em> and <em>t</em> is the result obtained from adding <em>s</em> and <em>t</em> together.
<em>s </em>+<em> t</em>
To get the answer you need to find out how many miles she bikes in 10minutes.
Divide 50minutes by 10 you get 5. Now you divide 10(miles) by 5 and you get 2. So it means that in 10minutes she bikes 2miles. Now you need to know how many miles she bikes in 90minutes so if she bikes 2 in 10 then because 90:10=9 you do 2*9=18. She can bike 18miles in 90minutes. :))
Equation of an ellipse
→having center (0,0) , vertex (
and covertex
and focus
is given by:

As definition of an ellipse is that locus of all the points in a plane such that it's distance from two fixed points called focii remains constant.
Consider two points (a,0) and (-a,0) on Horizontal axis of an ellipse:
Distance from (a,0) to (c,0) is = a-c = 
Distance from (-a,0) to (c,0) is = a + c = 
a -c + a +c
= a + a
= 2 a →(Option A )
Answer:
randomly requiring half the drivers to drive with sunglasses and the other half to drive without sunglasses.
Step-by-step explanation:
When employing an independent group design in a research or experimental study, the different groups in the study are assigned entirely different subjects such that, subjects in the treatment group are different from those in the control group. Therfore, adopting an independent group design in the scenario described above means diving the subjects into two at random with one half driving with sunglasses and the other half having to drive without it.