As Marion ( Tattingstone school) said, "This is a trick question because if you add 4 odd numbers together you get an even number".

But the real surprise was how many different ways you found to do it!

Marion said "So what you do is put 2 cakes in one bag and 3 cakes in another. Then you put the bag with 3 cakes inside the bag with 2. That makes 5 cakes. Then put 5 more in one and 5 more in the last".

Erick from Sciennes Primary School, Edinburgh
You put five cakes into three different bags. Then you put one bag with five cakes into the empty one.

Mable from Henry Park Primary School "Label the bags A, B, C, and D. put 5 cakes each into A, B, and C. Then, put the 3 bags into D. Thus, there are 5 cakes each in A, B, and C, while there are 15 cakes in D.

Matthew and Steven (Moorfield Junior) thought the same way. "We put 5 cakes in one bag, 5 in another and 5 in another. Then we put the three bags into one bag. Francesca, Calum and Elliot (Yerbury Primary School London) "In the smallest bag you put 1 cake and then you put it in a bigger bag which has 2 cakes therefore making the bigger bag have 3. In the other bags you have 7 and 5."

Evan (Australian International School, Singapore) "Here is the solution for the cookie problem in the smaller bag put 1, in the second smallest put 2, the third smaller 4 and the larger 8 put the smaller in the second smallest and so on."

Now here's a completely different trick from Ting (MLC, Melbourne, Australia) "You can put any amount of amount of cakes in the bag, write down 4 different numbers ( that are odd of course) and cut them out. Then put a number in each bag. I thought of this solution because if you use whole numbers (not including zero) you can't do it unless you use even numbers. "