- The marginal cost curve intersects the average cost curve:   In the minimum point of the latter.

- The members of the European Commission:   Are independent and Member States are committed not to instruct them.

- The ostrich is faster than the cheetah, which is faster than the falcon; the lion is slower than the cheetah. Therefore:   The lion is slower than the ostrich, but it could be faster than the falcon.

- Three young people (A, B, C) aged 24, 26 and 28, not necessarily in that order, are queuing up to apply for the issue of a three-year degree certificate. Twenty-eight-year-old B is immediately behind C; the twenty-six-year-old, who is first in the queue, is not called A. Who is the last one of the three in the queue and how old is s/he?   A, and s/he is 24.

- Three young people (A, B, C), of British, French and Spanish nationality, not necessarily in that order, are queuing up at the PR Office to pick up application forms for training periods. The Spaniard, B, is immediately behind C; the Briton, who is first in the queue, is not called A. Who will be the last one to pick up the documents, and what nationality is s/he?   A, and s/he is French.