At 10am today the tickets go on sale for the next Edinburgh Secret Society event.  Details here.  On Friday I published this puzzle……

To make French toast, I have to fry both sides of a slice of bread for 30 seconds. However, my frying pan can only hold two slices of bread at once. How quickly can I make three slices of French toast?

If you have not tried to solve it, have a go now.  For everyone else, the answer is after the break.

The answer is 1.5 minutes.  You place in 2 slices then, after 30 seconds, turn one over and remove the other and replace it with the third piece of bread.  30 seconds later you remove the first slice, turn the third over and place the second slice back again.  30 seconds after that you are all done!  Did you solve it?  Any other answers?

I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for theKindle (UK here and USA here) and on the iBookstore (UK here in the USAhere).


  1. Alternate answer which only requires two slices of bread in the first place: put both slices in the pan; after 30 seconds turn one over, slice the other in half (to make two slices half the thickness of the original) and put one of these, raw side down, in the pan; after further 30 seconds remove those two and fry the remaining raw side for 30 seconds. This will leave you with two thin slices of French toast for those with delicate appetites and one chunkier one. It’s a rubbish answer, of course. Far better to have three chunky slices, but these are frugal times.

  2. If the bread is square then the third piece, if cut in half, will fit in the pan at the same time as the other two !
    30 secs each side = 60 secs.

    1. The puzzle said the pan can only fit 2 slices of bread, why would cutting the third in half suddenly mean you could fit more bread in?

    2. If it’s a circular pan, then it must have a diameter at least equal to two slices of bread. Cutting the third slice in half will then make them all fit, as you will have two side by side east-west across the pan, making the width of one slice north-south, and so you can squeeze the two other halves in beside them.

    3. Not all frying pans are circular. It is stated that only 2 slices can fit in the pan, so it is implied that the geometry does not allow all three to fit at once.

    4. Of course you can find (or build) frying pans of every imaginable shape. However, the vast majority of pans are circular, and this is a great alternate answer…

    5. Well if we’re allowed to assume that “my frying pan can only hold two slices of bread at once” is insaccurate, I’m going to assume that “I have to fry both sides of a slice of bread for 30 seconds” is inaccurate too, make it five seconds by turning the heat up A LOT, and now I can do the whole lot in ten seconds.

  3. I still prefer my solution of buying a special frying pan for toast, that can do both sides of a slice at once. Then it only takes 1 minute

  4. On a purely practical note if you put the third slice on top of the two cooking slices you will pre-warm it and reduce the cooking time slightly.

    Similarly, I have produced 4 slices of toast at the same time from our two slice toaster by putting 2 slices in each slot and once they are toasted on the outside faces, reversing them to toast the inside faces. It’s not much quicker but you get 4 slices at the same time rather than 2 cooling slices and 2 hot slices.

  5. Here’s another puzzle: three tasks need to be done, each requiring n minutes. Each task can be split into two periods of n/2 minutes. It is possible to carry out two tasks in parallel. How quickly can all the tasks be completed given that 3*n/2=3n/2?

  6. That’s not haw ah would normally do it.
    Ah taike two slaices of bread, half a jarw of southern peanut butter on one slaice, half a jarw of mommas own graipe jelly on the other. Cover both with slaices of bananas and them breads together to a sandwich.
    Dip the sandwich in batter and deep fry for three minutes.
    Repeat five times and you got a lunch.
    Thank you for reading, thank you very much…

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