Who is asking: Student
Level of the question: Middle

Question: 1) The average of 12 is 5. The average of of 8 of these numbers ia 6. What is the average of the other four.

2)Mathilda is playing a mathematical game with Matthew. Each player starts from a point, then moves in a straight line to a second point,then to a third and so on. The moves are not made randomly, but are determined by a mathematical rule. The object of the game is to find the rule. It is Mathilda's turn to move on the grid . She starts at point M (3,9), moves to point N (2,4) and then to point O (0,0). Given Mathilda's rule, what could be the coordinates of the next point to which she might move?



Question 1)

The average of 12 numbers is 5. What is the sum of the 12 numbers?
The average of 8 of these numbers is 6. What is the sum of these 8 numbers?
What is the sum of the 4 remaining numbers? What is their average?

Question 2)

Look at the coordinates of the three points that Mathilda lands on in a table.

  x coordinate y coordinate
1st point 3 9
2nd point 2 4
3rd point 0 0

What is the relationship between the x and y coordinates?
What pattern do you see in the x coordinates? Using this pattern what would the next x coordinate be?

Notice that the question asks "what could be the coordinates of the next point...?" You might see a different pattern than your classmates and hence have a different next point than they do. The important point is to see a pattern, be able to explain it and show how you use the pattern to find your next point.