17. Jeroen writes a list of 2019 consecutive integers. The sum of his integers is 2019.
What is the product of all the integers in Jeroen's list?
20. The "heart" shown in the diagram is formed from an equilateral triangle ABC and two congruent semicircles on AB. The two semicircles meet at the point P. The point O is the centre of one of the semicircles. On the semicircle with centre O, lies a point X. The lines XO and XP are extended to meet AC at Y and Z respectively. The lines XY and XZ are of equal length.
What is $\angle ZXY$ ?
22. A function f satisfies the equation (n − 2019) f (n) − f (2019 − n) = 2019 for every integer n.
What is the value of f (2019) ?
25. Two circles of radius 1 are such that the centre of each circle lies on the other circle. A square is inscribed in the space between the circles.
What is the area of the square?