Hello Minniemouseluv, (40-x)(36) + (92 - 40) * 48 = C There were 92 people total, 40 of which were under 12, leaving the (92-40) people over 12. Each ticket for them cost 48 dollars, so the revenue for people over 12 is (92-40)(48) There's an unknown number of people that's under 3. The kids that are under 3 do not generate revenue, so they're not a part of the cost. Essentially, they are x = 40 - ((C - 2496)/ 36)