There were 137 tickets purchased for a major league baseball game the lower box tickets cost $12.50 and the upper box tickets cost $10 the total amount of money spent was $1,502.50 how much of each kind of ticket

lower box = x

upper box = y

x+y=137

x=137-y

12.50x + 10y=1502.50

12.50 (137-y) + 10y=1502.50

1712.5-12.50y+10y=1502.50

1712.5-2.50y=1502.50

-2.5y=-210

y=-210/-2.50 = 84

y = 84

x=137-84=53

53 lower box tickets

84 upper box tickets