Don't worry, I have sorted it out finally:
It is:
Adults = x
Students = y
So x + y = 45
x = 45 - y....(1)
Adult tickets are R375 and Student Tickets are R200, which means that 375x + 200y = 9875....(2)
So then just sub (1) into (2) and do the sum.
Students are 40 and Adults are 5.