( X 10) + ( X 1) = 42 chewing-gums
( X 10) + ( X 1) = 25 chewing-gums
( X 10) + ( X 1) = 18 chewing-gums
( X 10) + ( X 1) = 30 chewing-gums
( X 10) + ( X 1) = 56 chewing-gums
( X 10) + ( X 1) = 61 chewing-gums