Agroup of children, adults, and senior citizens attended three different art exhibits that have different ticket prices for each age group. let c represent the number of children, a represent the number of adults, and s represent the number of senior citizens. the system represents the cost of each type of ticket and the total cost of the tickets for all three exhibits. what are the number of children, adults, and seniors that attended these three exhibits? 6c + 7a + 2s = 990 3c + 3a + 4s = 430 2c + 4a + 4s = 480 a) c = 120, a = 30, s = 30 b) c = 20, a = 40, s = 70 c) c = 100, a = 50, s = 5 d) c = 100, a = 50, s = 20