Inequalities

There are 47 NRICH Mathematical resources connected to Inequalities
In Between
problem

In Between

Age
16 to 18
Challenge level
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Can you find the solution to this algebraic inequality?
Biggest enclosure
problem

Biggest enclosure

Age
14 to 16
Challenge level
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Three fences of different lengths form three sides of an enclosure. What arrangement maximises the area?
Eyes Down
problem

Eyes Down

Age
16 to 18
Challenge level
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The symbol [ ] means 'the integer part of'. Can the numbers [2x]; 2[x]; [x + 1/2] + [x - 1/2] ever be equal? Can they ever take three different values?
Approximating Pi
problem

Approximating Pi

Age
14 to 18
Challenge level
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By inscribing a circle in a square and then a square in a circle find an approximation to pi. By using a hexagon, can you improve on the approximation?
Mediant madness
problem

Mediant madness

Age
14 to 16
Challenge level
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Kyle and his teacher disagree about his test score - who is right?
Plutarch's Boxes
problem

Plutarch's Boxes

Age
11 to 14
Challenge level
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According to Plutarch, the Greeks found all the rectangles with integer sides, whose areas are equal to their perimeters. Can you find them? What rectangular boxes, with integer sides, have their surface areas equal to their volumes?
Unit Interval
problem

Unit Interval

Age
14 to 18
Challenge level
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Take any two numbers between 0 and 1. Prove that the sum of the numbers is always less than one plus their product?
Giants
problem

Giants

Age
16 to 18
Challenge level
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Which is the bigger, 9^10 or 10^9 ? Which is the bigger, 99^100 or 100^99 ?
Inequalities
problem

Inequalities

Age
11 to 14
Challenge level
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A bag contains 12 marbles. There are more red than green but green and blue together exceed the reds. The total of yellow and green marbles is more than the total of red and blue. How many of each colour there are in the bag?