### Bat Wings

Three students had collected some data on the wingspan of some bats. Unfortunately, each student had lost one measurement. Can you find the missing information?

### A Mean Tetrahedron

Can you number the vertices, edges and faces of a tetrahedron so that the number on each edge is the mean of the numbers on the adjacent vertices and the mean of the numbers on the adjacent faces?

### Pairs

Ann thought of 5 numbers and told Bob all the sums that could be made by adding the numbers in pairs. The list of sums is 6, 7, 8, 8, 9, 9, 10,10, 11, 12. Help Bob to find out which numbers Ann was thinking of.

# Archery

##### Stage: 3 Challenge Level:

Imagine picking up a bow and some arrows and attempting to hit the target a few times.

You may decide that you need to adjust the sight - perhaps the last person to use the bow was taller or shorter than you, and perhaps there is a sideways wind that you need to take into account.

Use the interactivity below to simulate this situation:
• adjust the sight to suit the new conditions

Can you work out the settings for the sight (coordinates) that give you the best chance of gaining a high score?

Present your conclusion in a way that provides convincing evidence that you have identified the optimum setting.

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