Live Problems - Stage 3 & 4

Each time you visit the NRICH site there will be some activities which are 'live'. That means we are inviting you to send us your solutions and we will publish a selection of them, along with your name and school. If you'd like to read more about what we're looking for, read this short article.

Stage 3 and 4 Toughnutslive

Stage: 3 Challenge Level: Challenge Level:1

These Stage 3 and 4 problems have not yet been solved. Can you be the first?

Red Card Blue Cardlive

Stage: 3 Short Challenge Level: Challenge Level:2 Challenge Level:2

Can you arrange the red and blue cards so that the rules are all followed?

Trapezium Archlive

Stage: 3 Short Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

Weekly Problem 27 - 2007
Ten stones form an arch. What is the size of the smallest angles of the trapezoidal stones?

Magic 7live

Stage: 3 Short Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

Weekly Problem 36 - 2015
Can you complete this magic square with the numbers from 7 to 15?

Equal Meanslive

Stage: 3 Short Challenge Level: Challenge Level:2 Challenge Level:2

Weekly Problem 36 - 2017
What value of x makes the mean of the first three numbers in this list equal to the mean of the other four?

Common Remainderlive

Stage: 3 Short Challenge Level: Challenge Level:2 Challenge Level:2

Weekly Problem 35 - 2017
144 divided by n leaves a remainder of 11. 220 divided by n also leaves a remainder of 11. What is n?