Problems

Age
Difficulty
Found: 2008

You meet another alien, whose name is Teddy. He asks you “Am I the kind who could ask whether I am a Goop?"
Can anything be deduced about Teddy?

You meet a couple, Dan and Daisy. Dan asks Daisy “Are you the kind who could ask me whether I am a Goop?"
What can be deduced about Dan and Daisy?

You meet an alien (either a Crick or a Goop) called Bobby. He asks you “Am I the kind who could ask whether the wizard is the kind who could ask whether I (Bobby) am the wizard?"
Do you now know for sure who the wizard is?

On the planet of Cricks and Goops, you then meet a strange alien who asks you “Am I the kind who could ask you the question I am now asking?"
What can be said about her?

You meet three friends: Alex, Bernie and Carol. Alex asked Bernie “Are you the kind who could ask Carol whether she is the kind who could ask you whether you two are of different kinds?".
You might realise that it is only possible to deduce the kind of one of the three friends. Which one and are they a Crick or a Goop?

You meet an alien (either a Crick or a Goop) called Charlie. He asks you “Are the wizard and I the same kind?"
Who is the wizard?

Mr Smith has seven children. He wants to send three of them to run some errands on a Saturday. We will send the first child at 1pm, the second child at 2pm and the third one at 4 pm. In how many ways can he choose them?

Katie is making a bouquet. She has \(12\) different flowers available, but wants her bouquet to be composed of exactly \(5\) of them. The order of the flowers in the bouquet doesn’t matter. In how many ways can she do this?

We have \(6\) digits available: \(1,3,4,5,7\) and \(9\). We wish to make a \(3\)-digit number with different digits but only using these \(6\) digits. How many ways are there of doing this? What if we want the digits within the number to be arranged in an ascending order - how many numbers are left?

David has \(15\) video games in boxes on his shelf. His family is visiting his aunt next week. He was asked to pick only \(4\) games to play on his cousin’s computer. In how many ways can he do this?