Mandeep's watch loses two minutes every hour. Adam's watch gains one minute every hour. Can you work out what time they arrived at the airport?
During the third hour after midnight the hands on a clock point in the same direction (so one hand is over the top of the other). At what time, to the nearest second, does this happen?
On a farm there were some hens and sheep. Altogether there were 8 heads and 22 feet. How many hens were there?
Chris and Jo put two red and four blue ribbons in a box. They each pick a ribbon from the box without looking. Jo wins if the two ribbons are the same colour. Is the game fair?
How many winning lines can you make in a three-dimensional version of noughts and crosses?
How many solutions can you find to this sum? Each of the different letters stands for a different number.
Charlie and Abi put a counter on 42. They wondered if they could visit all the other numbers on their 1-100 board, moving the counter using just these two operations: x2 and -5. What do you think?
Many numbers can be expressed as the difference of two perfect squares. What do you notice about the numbers you CANNOT make?
Using the digits 1 to 9, the number 4396 can be written as the product of two numbers. Can you find the factors?
Which is the bigger, 9^10 or 10^9 ? Which is the bigger, 99^100 or 100^99 ?
