Let the number of adults' tickets be x Let the number of children's tickets be y Money Money Type Number from from of of EACH ALL ticket tickets ticket tickets ------------------------------------------- adult's x $3.50 $3.50x children's y $2.75 $2.75y ------------------------------------------- TOTALS 108 ----- $351.75 The first equation comes from the second column.x + y = 108 The second equation comes from the last column. 3.50x + 2.75y = 351.75 Get rid of decimals by multiplying every term by 100: 350x + 275y = 35175 So we have the system of equations: . We solve by substitution. Solve the first equation for y: x + y = 108 y = 108 - x Substitute (108 - x) for y in 350x + 275y = 35175 350x + 275(108 - x) = 35175 350x + 29700 - 275x = 35175 75x + 29700 = 35175 75x = 5475 x = 73 = the number of adult tickets. Substitute in y = 108 - x y = 108 - (73) y = 35 children's tickets. Checking: 73 adults' is $255.50 and 35 children's is $96.25 That's 108 tickets. And indeed $255.50 + $96.25 = $351.75 Edwin