Quandaries and Queries 

Hello, My name is David. This question is from my son's grade 6 math class being asked by the teacher; The sum of two whole numbers is 63. The difference between the numbers is 10. Find all the possible pairs. Thanks Hi David, None: If the numbers sum up to 63 one must be odd and the other even. However, the difference between an odd number and an even number must be odd and hence can't be 10. 

