The school football team is hosting a fundraiser dinner. Tickets are $20 for adults, $15 for seniors, and $6 for children. The expression 20a + 15s + 6c represents the total sales for a adult, s senior tickets, and c child tickets. Mariel sold 6 adult, 4 senior, and 8 child tickets.

20a + 15s + 6c = 20 (6) + 15 (4) + 6 (8) = ? + ? + ?