18.Amy, Brian , Cheryl, Danny and Eric went to a concert. How many arrangements are possible when they sit in five adjacent seats if (a) Eric insists on sitting next to Cheryl? (b) Brian refuses to sit next to Danny ?
18.Amy, Brian , Cheryl, Danny and Eric went to a concert. How many arrangements are possible when they sit in five adjacent seats if (a) Eric insists on sitting next to Cheryl?(b) Brian refuses to sit next to Danny ?