Ben has 57 toys. 15 of them are new, 9 are his favorite ones; 2 are new and favorite. Ben is going to give away all of his toys that are neither new nor favorite. How many toys will he give away?
Ben has 57, 15 new, 9 favorite, 2 are new and favorite. so take 2 away from both and you get a total of 20 toys that are either new, or favorite so he has 37 remaining
since he had 57 toys and he is giving away all that are new and favorite you would subtract the 15 that are new and the 9 that are his favorite. that would leave you with 33 toys. he also has 2 that are his favorite and new and you would take that away too leaving you with 31 toys he would be giving away
