Step-by-step explanation:
3a.
there are 40 students.
each one had to get to school one way or another. so, all of them have to be in the table in one category.
I am just surprised that "car" is not an option there.
anyway, we have
11 + 7 + 9 + 6 = 33
so, there are 40-33 = 7 students left for the train category.
3b.
I cannot draw it for you.
but you need to consider the following table :
all 40 students are the full 360° of the circle.
school-bus are 11 students = 11/40 × 360 = 11×9 = 99°
public bus are 7 students = 7/40 × 360 = 7 × 9 = 63°
walk are 9 students = 9/40 × 360 = 9 × 9 = 81°
bicycle are 6 students = 6/40 × 360 = 6×9 = 54°
train are 7 students = 7/40 × 360 = 7 × 9 = 63°
as you can see, the sum is again 40 students and 360°.
you need to draw these 5 pie slices with these angles.
and in each slice you write the number of students in that category.
together, side by side, all 5 slices will fill the whole circle.
r²h.