Help for the Race to Wat Phnom

This page gives you help for each of the questions. You can se this page when you are learning to play the game but not in the competiion.

Question 1 - The Temple of Learning

This is the easiest question but you need to know a little bit about prime numbers. Prime numbers are numbers that do not have any factors (except 1 and the number itself). The first ten prime numbers are (2,3,5,7,11,13,17,23,29,31). There are an infinite number of primes.
Find two prime numbers that add up 32.

  1. Start with the prime number that closest to 32 and is less than 32. That number is 31.
  2. Subtract that number from 32 and see if the answer is a prime number.
    If it is you have solved the problem.
    32 - 31 = 1, 1 is not a prime number
  3. Try again with the next prime below that one.
  4. Keep doing this until the difference between 32 and the number is prime.
  5. 32 - 29 = 3 and 3 is a prime number. The problem is solved. The answer is 32 = 29 + 3

Question 2 - The Russian Market

This question also uses prime numbers, but this time the numbers are multipled together instead of added. It looks difficult, but there sre things you can check to make the question easier. This example will show you how to do that.
Find two prime numbers that multiply together to make 437.
To solve the problem you need to divide 437 by smaller prime numbers until you find one which divides into 437 without any remainder. However you don't need to try every prime number less than 437. You do it like this.

  1. If a x b = 437 then 437 divided by a has no remainder and 437 divided by b has no remainder.
  2. 437 is not even, so 2 is not a factor.
  3. Start at 3 and divide 437 by each prime number until you find one where there is no remainder.
  4. 437 = 19 x 23

Question 3 - Aeon Mall

This question uses square numbers. To do this question you need to find $x^2$ and then find the $\sqrt{x^2}$.
Find $x$ where $4x^2 + 1 = 677 $.
$4x^2 = 677 - 1 $
$4x^2 = 676 $
$x^2 = 676 \div 4 $
$x^2 = 169 $
$x = \sqrt{169} $
x = 13 To find the square root of a number use the list of square numbers. the first row has the squares from 1 - 9, the second row the squares from 10 - 19 and so on.

Question 4 - Sisowat Quay

This question also uses square numbers. To do this question you need to find two square numbers that differ by n.
Example - Find x and y where $x^2 - y^2 = 39 $ .
The easiest way to. solve this problem is to use the equation $x^2 = 39 + y^2 $ and add a square number to 39 until you find one where $x^2 + 39 $ is also a square number.