From the condition, you have these two equations 3a + 4c = 92 (1) 2a + 3c = 65 (2) To solve it, multiply eq(1) by 2 and multiply eq(2) by 3. You will get 6a + 8c = 2*92 (1') 6a + 9c = 3*65 (2') Now subtract eq(1') from eq(2'). You will get c = 3*65 - 2*92 = 11. To find "a", substitute c= 11 into equation (1) 3a + 4*11 = 92 3a = 92 - 44 3a = 48 a = 48/3 = 16. ANSWER. Adult's ticket price is $16; child's ticket price is $11.