what do you make of these puzzles? i think they re really good. many of our students wouldn t have heard of gchq prior to this challenge, and understanding that in actual fact they have the skill sets to be able to go into such areas is really good for them. has this made you think about a career in that world? definitely, yeah. i ve always been into, like, problem solving, critical thinking, like, what you ve got to do to solve things. that made me look at that side in much more detail. it is making me more interested in what this could lead to. hundreds of schools will be taking part in this challenge today. anyone initially bamboozled should take heart. in this classroom, what to many seemed mission impossible became mission accomplished. tim muffett, bbc news. well, we thought we d try and have a go at one of the questions ourselves. here it is for you to try at home.