Problems

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On a line, there are 50 segments. Prove that either it is possible to find some 8 segments all of which have a shared intersection, or there can be found 8 segments, no two of which intersect.

It is known that \[35! = 10333147966386144929 * 66651337523200000000.\] Find the number replaced by an asterisk.

10 people collected a total of 46 mushrooms in a forest. It is known that no two people collected the same number of mushrooms. How many mushrooms did each person collect?

10 magazines lie on a coffee table, completely covering it. Prove that you can remove five of them so that the remaining magazines will cover at least half of the table.

Construct a function defined at all points on a real line which is continuous at exactly one point.

In a square which has sides of length 1 there are 100 figures, the total area of which sums to more than 99. Prove that in the square there is a point which belongs to all of these figures.

Every point in a plane, which has whole-number co-ordinates, is plotted in one of \(n\) colours. Prove that there will be a rectangle made out of 4 points of the same colour.

One of \(n\) prizes is embedded in each chewing gum pack, where each prize has probability \(1/n\) of being found.

How many packets of gum, on average, should I buy to collect the full collection prizes?