Let the number of children's tickets be x Let the number of adult's tickets be y Money Money Type Number from from of of EACH ALL ticket tickets ticket tickets ------------------------------------------- children x $5 $5x adults y $10 $10y ------------------------------------------- TOTALS 50 ----- $350 The first equation comes from the second column.x + y = 50 The second equation comes from the last column. 5x + 10y = 350 So we have the system of equations: . We solve by substitution. Solve the first equation for y: x + y = 50 y = 50 - x Substitute (50 - x) for y in 5x + 10y = 350 5x + 10(50 - x) = 350 5x + 500 - 10x = 350 -5x + 500 = 350 -5x = -150 x = 30 = the number of children's tickets. Substitute in y = 50 - x y = 50 - (30) y = 20 adult tickets Checking: 30 childrens is $150 and 20 adults is $200 That's 50 tickets. And indeed $150 + $200 = $350 Edwin