Answer:
The greatest number of rectangles that can be cut from the piece of metal = 12
Explanation:The dimension of the piece of metal = 16cm x 20cm
That is:
Length of the piece of metal = 20 cm
Width of the piece of metal = 16 cm
The dimension of the rectangle = 6cm x 4cm
Length of the rectangle = 6cm
Width of the rectangle = 4cm
The diagram below illustrates how the rectangles can be cut from the piece of metal
Considering the diagrams drawn above, and counting the rectangles formed, we can conclude that the greatest number of rectangles will be cut using the approach on the left, hence the greatest number of rectangles that can be cut is 12