A Sudoku with clues as ratios.
What angle is needed for a ball to do a circuit of the billiard table and then pass through its original position?
Two buses leave at the same time from two towns Shipton and Veston on the same long road, travelling towards each other. At each mile along the road are milestones. The buses' speeds are constant. . . .
A ladder 3m long rests against a wall with one end a short distance from its base. Between the wall and the base of a ladder is a garden storage box 1m tall and 1m high. What is the maximum distance. . . .
A Sudoku with clues as ratios.
Mike and Monisha meet at the race track, which is 400m round. Just to make a point, Mike runs anticlockwise whilst Monisha runs clockwise. Where will they meet on their way around and will they ever. . . .
A garrison of 600 men has just enough bread ... but, with the news that the enemy was planning an attack... How many ounces of bread a day must each man in the garrison be allowed, to hold out 45. . . .
When Charlie retires, he's looking forward to the quiet life, whereas Alison wants a busy and exciting retirement. Can you advise them on where they should go?
The triathlon is a physically gruelling challenge. Can you work out which athlete burnt the most calories?
Find the area of the shaded region created by the two overlapping triangles in terms of a and b?
A Sudoku with clues as ratios or fractions.
Find the ratio of the outer shaded area to the inner area for a six pointed star and an eight pointed star.
A circular plate rolls in contact with the sides of a rectangular tray. How much of its circumference comes into contact with the sides of the tray when it rolls around one circuit?
The diagram shows a regular pentagon with sides of unit length. Find all the angles in the diagram. Prove that the quadrilateral shown in red is a rhombus.
Using an understanding that 1:2 and 2:3 were good ratios, start with a length and keep reducing it to 2/3 of itself. Each time that took the length under 1/2 they doubled it to get back within range.
Anne completes a circuit around a circular track in 40 seconds. Brenda runs in the opposite direction and meets Anne every 15 seconds. How long does it take Brenda to run around the track?
Points P, Q, R and S each divide the sides AB, BC, CD and DA respectively in the ratio of 2 : 1. Join the points. What is the area of the parallelogram PQRS in relation to the original rectangle?
Two boats travel up and down a lake. Can you picture where they will cross if you know how fast each boat is travelling?
Can you work out the fraction of the original triangle that is covered by the inner triangle?
Mainly for teachers. More mathematics of yesteryear.
My recipe is for 12 cakes - how do I change it if I want to make a different number of cakes?
A farmer is supplying a mix of seeds, nuts and dried apricots to a manufacturer of crunchy cereal bars. What combination of ingredients costing £5 per kg could he supply?
Two right-angled triangles are connected together as part of a structure. An object is dropped from the top of the green triangle where does it pass the base of the blue triangle?
Triangle ABC is equilateral. D, the midpoint of BC, is the centre of the semi-circle whose radius is R which touches AB and AC, as well as a smaller circle with radius r which also touches AB and AC. . . .
Making a scale model of the solar system
Two motorboats travelling up and down a lake at constant speeds leave opposite ends A and B at the same instant, passing each other, for the first time 600 metres from A, and on their return, 400. . . .
If the sides of the triangle in the diagram are 3, 4 and 5, what is the area of the shaded square?
A circle of radius r touches two sides of a right angled triangle, sides x and y, and has its centre on the hypotenuse. Can you prove the formula linking x, y and r?
In a race the odds are: 2 to 1 against the rhinoceros winning and 3 to 2 against the hippopotamus winning. What are the odds against the elephant winning if the race is fair?
Four jewellers share their stock. Can you work out the relative values of their gems?
Which is a better fit, a square peg in a round hole or a round peg in a square hole?
Build a scaffold out of drinking-straws to support a cup of water
A cyclist and a runner start off simultaneously around a race track each going at a constant speed. The cyclist goes all the way around and then catches up with the runner. He then instantly turns. . . .
Take any rectangle ABCD such that AB > BC. The point P is on AB and Q is on CD. Show that there is exactly one position of P and Q such that APCQ is a rhombus.
If it takes four men one day to build a wall, how long does it take 60,000 men to build a similar wall?
How long will it take Mary and Nigel to wash an elephant if they work together?
Two ladders are propped up against facing walls. The end of the first ladder is 10 metres above the foot of the first wall. The end of the second ladder is 5 metres above the foot of the second. . . .
What is the ratio of the area of a square inscribed in a semicircle to the area of the square inscribed in the entire circle?
Which dilutions can you make using only 10ml pipettes?
Read all about the number pi and the mathematicians who have tried to find out its value as accurately as possible.
Is it cheaper to cook a meal from scratch or to buy a ready meal? What difference does the number of people you're cooking for make?
Scientists often require solutions which are diluted to a particular concentration. In this problem, you can explore the mathematics of simple dilutions
The large rectangle is divided into a series of smaller quadrilaterals and triangles. Can you untangle what fractional part is represented by each of the ten numbered shapes?
Andy wants to cycle from Land's End to John o'Groats. Will he be able to eat enough to keep him going?
Two perpendicular lines lie across each other and the end points are joined to form a quadrilateral. Eight ratios are defined, three are given but five need to be found.
Can you work out which drink has the stronger flavour?
Can you fill in the mixed up numbers in this dilution calculation?
Which exact dilution ratios can you make using only 2 dilutions?
Which dilutions can you make using 10ml pipettes and 100ml measuring cylinders?
What's the most efficient proportion for a 1 litre tin of paint?