I get a tad annoyed when people pass these riddles around yet refuse to discuss their logic. Everyone always seems to have different answers and the truth is never revealed. So… Here is my solution to this riddle. 🙂

The Riddle reads as follows: “How many balls? 95{28148476ffc437209dc1edc2bb1735fee425a101a19f0038276a3a22ace885e0} People will get this wrong”
So assuming that the balls are supported by other balls and NOT counting the two dots on the question marks which some people count as balls I came up with the solution in the image above.
16 balls on the bottom layer. 9 in the red layer. 3 in the green layer and one in the yellow layer. It should be said that this would still work if the middle ball was left out on the red layer, giving us 29 balls instead.
Wrong solution
Many sites point to a different solution using 20 balls. It uses a 3-sided pyramid structure rather than a 4-sided pyramid structure. Note that this could also be done with 19 balls if you leave out the centre ball on the bottom layer.
However as you can see in the image, the angles would be very different for such a solution. In the riddle it is quite clear that the base layer has the balls positioned at a 90{2263dae43a8a11e2efe0bfa3331ab0d60f8e1a72fc91a3e0b3aea405158704f3} angle.
Think about it, if the pyramid had only three sides, the red balls on the far left and far right would only have two ball between them. See that image below. It is NOT possible. 🙂
