...Relax take sometime to... solve the puzzle, easy one you can do it!Good Luck...
Solved the following :
Using only numbers 1 till 9 and fill into the box below, (number cannot repeat), after filled all the numbers, whether count vertically, horizontally or diagonally, it have to be equal to 15.
Try it and times how long it takes for you to solved it, be truth to yourself before peeping the answer.
Note you may find the answer in reverse sequence from below, if you rotate the box, you'll should know what I mean.