Earlier today I set three puzzles from Terms & Conditions Apply, a free online game about website deviousness (that I made with Jonathan Plackett.) The puzzles in the game exaggerate the tricks websites use to extract our data.
1. Naughty negatives
Which button do you press if you don’t want marketing alerts?
Solution: Click the Yes button.
‘Avoid not clicking Yes’ is the same as ‘avoid clicking No’, which is the same as ‘click Yes.’
2) Cheeky checkboxes
How do you untick all checkboxes in three clicks? [Each box is either ticked or unticked]
Solution: click on an unticked box, then on a ticked box, then on the remaining unticked box.
STEP 1. When you click an unticked box, it stays unticked. The two other empty boxes, and four ticked boxes will change, leaving you with 5 unticked, and 2 ticked boxes.
STEP 2. Click on of the ticked boxes. You will then get six ticked and one unticked box.
STEP 3: Tick the remaining unticked box, to untick all the rest. (In fact, to solve the puzzle, go backwards, i.e. work out what is the final position you need to be in, and then the penultimate one, and so on.)
3) Tricky toggles
Each of the two toggles in the pop-up below has two positions: on and off. At least one of the toggles is set to off.
If you click I’m feeling lucky when both toggles are on, you will opt out of cookies. If, on the other hand, you click I’m feeling lucky when at least one of the toggles is off, then both toggles spin. When the toggles end their spin you have no idea which toggle is which, nor which way round the toggles are. (The toggles could have swapped positions with each other, and either one or both could be upside down. During the spin, however, a toggle that is on stays on, and a toggle that is off stays off. )
You are allowed to click the toggles between on/off positions as much as you like. What strategy guarantees you opt out of cookies with at most three clicks of I’m feeling lucky?
Solution: Click on both toggles. Press IFL. Click one toggle. Press IFL. Click on both toggles. Press IFL. (Here a ‘click’ means flip the toggle’s status from off to on, or vice versa.)
STEP 1. The question states that at least one of the toggles is off. Which means there are are three possibilities: 1) both toggles are off; 2) the left one is off; 3) the right one is off.
The solution involves taking care of each of these three possibilities one by one. The first one we deal with is case 1, when both toggles are off. If both toggles are off, then when you click on both toggles, both toggles are switched on, and a press of IFL opts you out of cookies. We are out with one press of IFL.
If, however, the original positions are as described in 2 or 3, when only one toggle is on, and one is off, then clicking both toggles means that, overall, the status stays the same: only one toggle is on, and the other id off. (We don’t know which.) When we press the IFL button now, the toggles spin.
STEP 2. When the spin ends, all we know is that one of the toggles is on, and the other is off. If we click one toggle, there are now only two possibilities: either both toggles are on, or both toggles are off. Press the IFL button now, and if both toggles are on we opt out of cookies. If both are off, then the toggles will spin.
STEP 3. When the spin ends, we know that both toggles are off. So we click on both of them, ensuring that they are both on. We press IFL, and we are done.
Another plug for the game!
The game Terms & Conditions Apply contains more than 25 tasks (including the ones above) that parody the tricks websites use to get you to do something you don’t want to do. They include word challenges, logic puzzles, dexterity tests and optical illusions.
I developed the game with Jonathan Plackett, of Wieden+ Kennedy, as a way of exposing internet deviousness – and having some fun at the same time. Enjoy!
I set a puzzle here every two weeks on a Monday. I’m always on the look-out for great puzzles. If you would like to suggest one, email me.
I’m the author of several books of puzzles, most recently the Language Lover’s Puzzle Book. I also give school talks about maths and puzzles (restrictions allowing). If your school is interested please get in touch.