List

Secondary Live Problems and Recent Solutions

Secondary Live Problems

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

The last day for submitting solutions to these live problems is Monday 14 October.

Take Three From Five
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Favourite

Take Three From Five

Age
11 to 16
Challenge level
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Caroline and James pick sets of five numbers. Charlie tries to find three that add together to make a multiple of three. Can they stop him?

Cuboid challenge
problem
Favourite

Cuboid challenge

Age
11 to 16
Challenge level
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What's the largest volume of box you can make from a square of paper?

Slick Summing
problem
Favourite

Slick Summing

Age
14 to 16
Challenge level
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Watch the video to see how Charlie works out the sum. Can you adapt his method?

Secondary Students' Solutions

Take a look at these recently solved problems.

Have you got it?
problem
Favourite

Have you got it?

Age
11 to 14
Challenge level
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Can you explain the strategy for winning this game with any target?
Wipeout
problem
Favourite

Wipeout

Age
11 to 16
Challenge level
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Can you do a little mathematical detective work to figure out which number has been wiped out?
m, m and m
problem
Favourite

M, M and M

Age
11 to 14
Challenge level
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If you are given the mean, median and mode of five positive whole numbers, can you find the numbers?

Charlie's delightful machine
problem
Favourite

Charlie's delightful machine

Age
11 to 16
Challenge level
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Here is a machine with four coloured lights. Can you develop a strategy to work out the rules controlling each light?

Pick's Theorem
problem
Favourite

Pick's Theorem

Age
14 to 16
Challenge level
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Polygons drawn on square dotty paper have dots on their perimeter (p) and often internal (i) ones as well. Find a relationship between p, i and the area of the polygons.
Tilted Squares
problem
Favourite

Tilted Squares

Age
11 to 14
Challenge level
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It's easy to work out the areas of most squares that we meet, but what if they were tilted?
Add to 200
problem
Favourite

Add to 200

Age
11 to 14
Challenge level
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By selecting digits for an addition grid, what targets can you make?
Cyclic Quadrilaterals
problem
Favourite

Cyclic Quadrilaterals

Age
11 to 16
Challenge level
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Draw some quadrilaterals on a 9-point circle and work out the angles. Is there a theorem?