Find the distance between j and k

Can somebody me out with this question

The midpoints of the sides of the large square are joined to form a smaller square. what is the area of the smaller square

The number of 8th graders who responded to a poll of 6th grade and 8 th graders was one fourtg of the number of 6th graders whi responded if a total of 100 students responddd to the poll how many of the students responded were 6 th graders