The image words are really too small, I have to use my handphone to expand the image to read it and it is still blur… maybe you have to upload the image as 2 images or fold the excess space between the questions and zoom in to take a picture.

(a) Total surface area = 2(8 x 7) + 2(8 x 3) + 2 (7 x 3 ) = 202 cm²

(b) Using prime factorisation,

          231

      /          \

3                  77

                 /           \

             7                11

                            /           \

                          11             1

So the sides are  3 cm by 7 cm by 11 cm

(c)  To make the largest cube, it would be 6 x 6 x 6 = 216 cm ³

Hence the remaining cubes = 231 – 216 = 15

Indeed, I cannot read the question.  Can’t even make the picture bigger as the resolution is too little.