- April 1999, All Stages

Problems

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Fencing Lambs

Stage: 2 Challenge Level: Challenge Level:1

A thoughtful shepherd used bales of straw to protect the area around his lambs. Explore how you can arrange the bales.

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Cut and Make

Stage: 2 Challenge Level: Challenge Level:1

Cut a square of paper into three pieces as shown. Now,can you use the 3 pieces to make a large triangle, a parallelogram and the square again?

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Bunny Hop

Stage: 2 Challenge Level: Challenge Level:1

What is the smallest number of jumps needed before the white rabbits and the grey rabbits can continue along their path?

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Highest and Lowest

Stage: 2 Challenge Level: Challenge Level:1

Put operations signs between the numbers 3 4 5 6 to make the highest possible number and lowest possible number.

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How Many Eggs?

Stage: 2 Challenge Level: Challenge Level:2 Challenge Level:2

Peter, Melanie, Amil and Jack received a total of 38 chocolate eggs. Use the information to work out how many eggs each person had.

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The 24 Game

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

There are over sixty different ways of making 24 by adding, subtracting, multiplying and dividing all four numbers 4, 6, 6 and 8 (using each number only once). How many can you find?

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Count the Trapeziums

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

How many trapeziums, of various sizes, are hidden in this picture?

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Lesser Digits

Stage: 3 Challenge Level: Challenge Level:1

How many positive integers less than or equal to 4000 can be written down without using the digits 7, 8 or 9?

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Floored

Stage: 3 Challenge Level: Challenge Level:1

A floor is covered by a tessellation of equilateral triangles, each having three equal arcs inside it. What proportion of the area of the tessellation is shaded?

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Nines and Tens

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

Explain why it is that when you throw two dice you are more likely to get a score of 9 than of 10. What about the case of 3 dice? Is a score of 9 more likely then a score of 10 with 3 dice?

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A Chordingly

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

Find the area of the annulus in terms of the length of the chord which is tangent to the inner circle.

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Mindreader

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

A little bit of algebra explains this 'magic'. Ask a friend to pick 3 consecutive numbers and to tell you a multiple of 3. Then ask them to add the four numbers and multiply by 67, and to tell you. . . .

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Just Rolling Round

Stage: 4 Challenge Level: Challenge Level:3 Challenge Level:3 Challenge Level:3

P is a point on the circumference of a circle radius r which rolls, without slipping, inside a circle of radius 2r. What is the locus of P?

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Upsetting Pitagoras

Stage: 4 and 5 Challenge Level: Challenge Level:1

Find the smallest integer solution to the equation: 1/x^2 + 1/y^2 = 1/z^2

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Be Reasonable

Stage: 5 Challenge Level: Challenge Level:2 Challenge Level:2

Prove that sqrt2, sqrt3 and sqrt5 cannot be terms of ANY arithmetic progression.

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Circles Ad Infinitum

Stage: 5 Challenge Level: Challenge Level:2 Challenge Level:2

A circle is inscribed in an equilateral triangle. Smaller circles touch it and the sides of the triangle, the process continuing indefinitely. What is the sum of the areas of all the circles?

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