This is part of our collection of Short Problems.

You may also be interested in our longer problems on Probability - Stage 3.

Printable worksheets containing selections of these problems are available here

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### Birthday Party

The 30 students in a class have 25 different birthdays between them. What is the largest number that can share any birthday?

problem

### Would you like a Jelly Baby?

What is the smallest number of jelly babies Tom must take, to be certain that he gets at least one of each flavour?

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### Half and Half

Two of the four small triangles are to be painted black. In how many ways can this be done?

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### Strange dice

If two of these unusually numbered dice are thrown, how many different sums are possible?

problem

### School Dinners

Our school dinners offer the same choice each day, and each day I try a new option. How long will it be before I eat the same meal again?

problem

### Monkey Puzzle

What is the probability that all three monkeys left the cafe wearing the wrong hats?

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### Pieces of Eight

Two of the triangles in the diagram are shaded black. What is the probability the resulting figure has at least one line of symmetry?

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### Almost Constant Digits

How many 10-digit numbers containing only 1s, 2s and 3s can you write?

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### Counting Socks

Can you work out the smallest number of socks Rachel needs to take out of the box to be guaranteed a pair?