N3A2TNp9

Answer to problem 9:

1.   12 and 40; 40 and 27; 40 and 28; 40 and 11; 27 and 28

2.   Answers may vary. Examples: To get a sum greater than 50, you only need to add 11 more to 40. 12 is more than 11, so 12 plus 40 would be greater than 50; or,
I know that half of 50 is 25, so if I add 27 (which is more than half of 50) and 28 (which is more than half of 50), I will get a sum greater than 50.