Trick or Treat

Mrs. Smith had emptied packets of chocolate-covered mice, plastic frogs and gummi-worms into a cauldron for treats.

 There were 9 mice, 5 frogs and 4 worms. Trixie was allowed to dip into the cauldron for a treat but had to do it without peeping. What treat is Trixie most likely to pick out?

Trixie wanted to be certain of pulling out at least one of each type of the treats. How many times would Trixie need to be able to dip into the cauldron to do this?

If Trixie had pulled out a mouse, would her brother Nick be more likely to pick out a mouse too, or a frog or worm instead?

Why do this problem?

This activity can be used as a nice straightforward introduction to probability.

Possible approach

This can be done practically with a large group with a box containing items to represent those in the challenge.

Key questions

Why have you decided on this?

Possible extension

Change the figures and suggest variations, for example when items are taken out they could then be replaced before the next selection.