The prize for completing the Tokyo Metro August true-or-false quiz is a papercraft Hibiya Line subway train! ;o)
As before (April, May, June and July) you need to answer 6 true-or-false questions correctly, so if you don't understand Japanese you could simply guess your way through (a red "正解" after choosing your answer means the answer was correct, a blue "不正解" means it was wrong - or you can look at the answers at the bottom of this post);
If you got all six answers right, at the end you will see a blue button near the bottom saying "プレゼントをダウンロード" that will let you download the PDF parts file (otherwise it will say "もう一度チャレンジ！" and take you back to the beginning so you can try again).
Good luck and have fun!
(Tokyo Metro May July Test answers: Q1x, Q2o, Q3o, Q4x, Q5x and Q6o)