In this addition each letter stands for a different digit, with S standing for 3. What is the value of YxO?
Can you place the nine cards onto a 3×3 grid such that every row, column and diagonal has a product of 1?
If it takes 852 digits to number all the pages of a book, what is the number of the last page?
What is the largest number Sophie can use to have seven positive integers with a mean of 7?
If Clara spends £23 on books and magazines, how many of each does she buy?
Each digit of a positive integer is 1, 2 or 3, and each of these occurs at least twice. What is the smallest such integer that is not divisible by 2 or 3?
Weekly Problem 31 - 2017
The triangle HIJ has the same area as the square FGHI. What is the distance from J to the line extended through F and G?
Arrange the numbers 1 to 16 into a 4 by 4 array. Choose a number. Cross out the numbers on the same row and column. Repeat this process. Add up you four numbers. Why do they always add up to 34?
I start with a red, a blue, a green and a yellow marble. I can trade any of my marbles for three others, one of each colour. Can I end up with exactly two marbles of each colour?
