Multiple choice general knowledge math & puzzles Mary has travelled half of a journey. She has gone 9km. How long is her journey? 16 km 18 miles 18 km 14 km Reveal answer Fill a bubble to check yourself C Correct answer Explanation If half of the journey is 9 km, the full journey is 9 km * 2 = 18 km. Option 347367 is incorrect because it uses 'miles' instead of 'km', and the other options are incorrect multiples.