These are known errors/typos in the text A First Look at Graph Theory by John Clark and Derek Allan Holton. If you find any not listed here, let me know.

• Page 6. Problem 5. C_2 and C_3 should be swapped in the last sentence of the second paragraph. It should read:
  "As a particular example, consider the following graph G where, for example, C_3's transmitter is within 200 kilometres of those of C_1, C_2, C_4 and C_5."

• Page 59. Exercise 2.3.3 Assume G is simple. Otherwise the statement to be proven can be disproved by a connected graph whose only cycle is a loop.

• Page 246. Exercise 7.2.11 Assume D is simple. Otherwise the statement to be proven is not true.