2 out of 3
How does the perimeter change when we fold this isosceles triangle in half?
2 out of 3
Look at the times that Harry, Christine and Betty take to pack boxes when working in pairs, to find how fast Christine can pack boxes by herself.
3 out of 3
Can you explain why a sequence of operations always gives you perfect squares?
3 out of 3
Take any pair of two digit numbers x=ab and y=cd where, without loss of generality, ab > cd . Form two 4 digit numbers r=abcd and s=cdab and calculate: {r^2 - s^2} /{x^2 - y^2}.
3 out of 3
Brian swims at twice the speed that a river is flowing, downstream from one moored boat to another and back again, taking 12 minutes altogether. How long would it have taken him in still water?
3 out of 3
Let S1 = 1 , S2 = 2 + 3, S3 = 4 + 5 + 6 ,........ Calculate S17.
3 out of 3
Semicircles are drawn on the sides of a rectangle. Prove that the sum of the areas of the four crescents is equal to the area of the rectangle.
3 out of 3
Can you use the diagram to prove the AM-GM inequality?
3 out of 3
Can you explain what's happening with these numbers?
3 out of 3
The opposite vertices of a square have coordinates (a,b) and (c,d). What are the coordinates of the other vertices?
