Answer:
Step-by-step explanation:
Number of children = c
Number of adults = a
Total people = 390
a + c = 390 ------------------ (I)
Admission fee for 'c' children = 20 * c = 20c
Admission fee for 'a' adult = 35 * a = 35a
Total amount = $ 10650
35a + 20c = 10650 -------------(II)
Multiply equation (I) by (-20)
(I)*(-20) Â -20a - 20c = - 7800
(II) Â Â Â Â Â 35a + 20c = 10650 Â Â { Now add and so 'c' will be eliminated}
       15a       = 2850
a = 2850/15
a = Â 190
Plug in a = 190 in equation (I)
190 + c = 390
     c =  390 - 190
c = 200
Number of children = 200
Number of adults = 190
