The Twelve Mince-Pies

The Twelve Mince-Pies
Twelve mince-pies are placed on a table to form six straight rows with four pies in every row.
Move only four mince-pies to new positions to form seven straight rows with four in every row.
Which four would you move, and where would you place them?
Mrs Smiley’s Christmas Present
Mrs. Smiley's six grandchildren gave her, as a Christmas present, a square patchwork quilt, which they had
made themselves.
It was made of small silk squares all the same size - with fourteen small squares on each side.
Each grandchild had made a part of the quilt that was a perfect square (all six parts being different in size).
In order to join the six parts up to form the square quilt they had to unpick one part into three separate
pieces.
Can you show how the joins might have been made? Of course, no part can be turned over.
The Christmas Pudding
With straight line segments cut the Christmas pudding into two parts, so that
each part is exactly the same size and shape, without touching any of the plums.
Treat it as a flat disc, not as a sphere.
A Calendar Puzzle
If the end of the world should come on the first day of a new century, can you
work out the chances that it will happen on a Sunday?