This is part of our collection of Short Problems.
You may also be interested in our longer problems on Conjecturing and Generalising.
problem
1 out of 3
Bishop's Paradise
Age
11 to 14
Challenge level
1 out of 3
Which of the statements about diagonals of polygons is false?
problem
1 out of 3
Counting Fish
Age
14 to 16
Challenge level
1 out of 3
I need a figure for the fish population in a lake. How does it help to catch and mark 40 fish?
problem
2 out of 3
Little Difference
Age
14 to 16
Challenge level
2 out of 3
What is the value of $2015 \times 2017$ - $2016 \times 2016$?
problem
2 out of 3
Last-But-One
Age
14 to 16
Challenge level
2 out of 3
What is the last-but-one digit of 99! ?
problem
3 out of 3
Producing an Integer
Age
14 to 16
Challenge level
3 out of 3
Multiply a sequence of n terms together. Can you work out when this product is equal to an integer?
problem
3 out of 3
Super Computer
Age
14 to 16
Challenge level
3 out of 3
What is the units digit of the given expression?