As shown in the figure, AA' = 5, AB = 6, BB' = 3, the minimum value of A'M + MB' is (Figure is not to scale)
Key: 10
6.
If a polygon has the sum of its interior angles less than 2015 degrees. The maximum number of sides is...
Key: 13
Hard level
1. Let a, b, c be three positive integers with a ≤ b ≤ c such that (1 + (1 + 1/a) (1 + 1/b)(1 + 1/c) = 3. There are ... such triples.
Key: 3