### In Particular

Write 100 as the sum of two positive integers, one divisible by 7 and the other divisible by 11. Then find formulas giving all the solutions to 7x + 11y = 100 where x and y are integers.

### For What?

Prove that if the integer n is divisible by 4 then it can be written as the difference of two squares.

### Ordered Sums

Let a(n) be the number of ways of expressing the integer n as an ordered sum of 1's and 2's. Let b(n) be the number of ways of expressing n as an ordered sum of integers greater than 1. (i) Calculate a(n) and b(n) for n<8. What do you notice about these sequences? (ii) Find a relation between a(p) and b(q). (iii) Prove your conjectures.

# Training Schedule

##### Stage: 4 Challenge Level:

Joseph from Park View Community School sent us the following solution:

Find the percentage away from the world record for each event. Increase the 3 lowest events by 20% and accordingly maintain current levels for the 3 greatest events. increase performance by 10% on the remaining event. I calculated all points including all percentage increases as well using excel.