How many students are there in the group?

Question

Some students arranged themselves into a circle and are then counted off consecutively from number 1. Student 20 is directly opposite to student 53. How many students are there in the group?

 

a. 53

b. 58

c. 66

d. 84

 

Answer 1

The answer is C. 

 

Draw a circle. Put 20 anywhere. Then directly accross from 20 on the circle write 53. Draw a line(diameter) all the way accross from 20 to 53. 

 

Then do 53-20= 33 students. These are how many students are on one side of the diameter(on the circumference) that connects from 20 to 53. So if there is 33 students on one side of a diameter, then there is 33 students on the other side of the diameter! So 33(2) or 33 + 33 = 66 students!

I hope this helped!