<PRE><B>Question 15676</B>
Let no: of adults be x
Cost of tickets for x adults = 12x
Let no: of children be y
Cost of tickets for y children = 4y
Total no: of tickets sold = x + y = 130 ----(1)
Total amount received     =12x + 4y = 840 ----(2)
Equation (2) can be reduced to
                            3x + y = 210 ----(3)  (this is obtained by dividing                the equation with 4)
Subracting (1) from (3) we get
               2x = 80 
                x = 40 
No: of adults = 85
x + y = 130
40 + y = 130
y = 130 - 40 = 90
No: of children = 90</PRE>