a) Show (by giving an example other than the one provided in the lecture) that two-dimensional parity checks can correct and detect a single bit error. [5 marks] b) Using examples, demonstrate that in general 2-bit errors can be detected but not corrected. To answer this question you should provide example diagrams where 2-bit errors exist. For each example you should explain why the error can be detected but not corrected. You should explain why the examples that you have chosen cover all the general cases of where errors might be (no help with what the general cases are, so think!). [15 marks]