Seven small pictures, all square or rectangular, with sides measuring a whole number of inches and each with a different area, have frames exactly one inch wide.

In each case the area of the frame is either the same as the area of the picture or a multiple of it.

The frames are removed and the pictures are fitted together like a jigsaw to make a rectangle of length 12 inches.

Find the dimensions of the pictures, show how they fit together to make a rectangle, and find the width of the rectangle.