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
problem
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?
problem
Half and Half
Two of the four small triangles are to be painted black. In how many ways can this be done?
problem
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?
problem
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?
problem
Almost Constant Digits
How many 10-digit numbers containing only 1s, 2s and 3s can you write?
problem
Counting Socks
Can you work out the smallest number of socks Rachel needs to take out of the box to be guaranteed a pair?