All Change.

This grid consists of 8 squares. On 3 of the squares there are white counters and on another 3 there are black counters.

The object of the challenge is to reverse the positions of the black and white counters.

only one counter can be moved at a time and only to an empty adjacent square. No diagonal moves are allowed.

What is the smallest number of moves?

Quick about it

If a = 1, b = 2, c = 3, d = 4......y = 25 and z = 26

What is the value of (x - a)(x - b)(x - c)......(x - y)(x - z)?

If you spend more than 30 seconds on this, you have spent too long - but think about it first!!!