There are 17 persons going for dinner. If we want to distribute them in groups, then the condition will be-4 groups with one person left. If the condition is that in every four persons, one is to get dine free, then it means in four groups, where are 16 people, 4 will dine free. Left,(16-4+1=)13 people who will have to pay for the dinner. So, 13*35=$455, which is the answer.