Question 21
Emily has a transparent sheet divided into squares, some coloured black as shown. Which other sheet can be combined with hers to produce an entirely black rectangle?
Original source choices (retained):
A.
B.
C.
D.
E.
Source consistency task: With the 3×4 grids aligned (flips and half-turns allowed), determine whether any original option covers all clear cells. Explain the printed key D and identify its smallest repair. This is an essay; original option images are unchanged.
Original source choices (retained):
A.
B.
C.
D.
E.
Source consistency task: With the 3×4 grids aligned (flips and half-turns allowed), determine whether any original option covers all clear cells. Explain the printed key D and identify its smallest repair. This is an essay; original option images are unchanged.