Puzzle A Puzzle B

I have a large container of fruit that contains only bananas, apples and peaches. The container has 14 bananas, 8 red apples and 11 green apples. If the total number of pieces of fruit is four times the number of apples in the container, how many peaches are in the container? Answer: 43 peaches (14 bananas, 19 apples, 76 pieces of fruit in total)

You have a 2-digit number. When you reverse the digits, you get a different 2-digit number. You subtract the smaller number from the larger number to get the difference between them. For example: If you start with 81, you then reverse it to get 18. 81 – 18 = 63. If you’d started with 82, you’d have got 82 - 28 = 54. What is the smallest difference you can get? Answer: I make it 9 (various options, such as 32-23, or 54-45). The only way to get less would be if the digits were the same, although it states they must reverse to give a different number, so this can’t happen. Can you show why the difference is always a multiple of 9….?