When W.G. invited us to his party he rewired the buttons' panel in the elevator and placed next to it a note:

Welcome.

The fun starts here and now. Originally the numbers were in sequence in a way that numbers 1 and 2 were neighbors - horizontally or vertically, 2 and 3 likewise and so on.

Now on 8 of 16 buttons the numbers were erased and then on 4 additional buttons the original numbers were replaced by the wrong ones.

Restore the original layout, press button 15 and join the fun!

Pressing any other button will get you 90 seconds or less of elevator music and a free ride to a wrong floor...

Can you locate the correct button?

**
**

** -x--x-11--x-
-8-16--9--x-
-6--x--x--4-
-x--x-14--2-
**

**
**
* Credit due to Mr Bob Stanton*

A drawer is divided into 9 square boxes, creating a 3*3 grid.

Your task is to create a "magic square" by putting a distinct amount of money in each of the boxes in a way that all of the 8 sums (vertical, horizontal and diagonal) will be the same.

Only standard American coins are allowed, i.e. 1,5,10,25,50, and 100c.

What is the minimal amount of coins ?

Show their distribution.

Three test tubes contain numbered balls. The first tube can contain three balls, the middle tube two, and the last tube only one. They start out in the configuration shown at left, and your task is to move one ball at a time from one tube to another without exceeding the tube's capacity, until the numbered balls are in the configuration on the right.

What's the minimum number of moves of individual balls and what's the sequence of moves?

| | | |
|3| | | ====> |3| | |
|1| |2| | | |2| | | |1|
= = = = = =

From Daily Brain Games calendar 2020, by HAPPYneuron, Andrews McMeel Publishing, Kansas City, MO. Puzzle for July 10.