其它
Becky is separating 53 cherries into bag A, bag B and bag C. It is known that there are even number of cherries in both bag A and bag B. Could you tell whether the number of cherries in bag C is even or odd number? 
Overseas Competition->Knowledge Point->Number Theory Modules->Odd and Even Numbers
Number of cherries in bag C: 53 (odd number) - even - even  Number of odd character = 1  Therefore, the number of cherries in bag C is odd. 