4 7 0 3 2 9 8 6 5 1
Find a way to write the digits 1 through 9 in sequence, so that the numbers determined by any two consecutive digits are divisible either by 7 or by 13.
There are 12 different chocolates placed on a table along a straight line. In how many ways can a person choose 4 of them such that no 2 of the chosen chocolates lie next to each other?
Arrange the number 1 to 9 in the boxes below so that each line of 3 boxes sums to 14(3 numbers have already been placed)