A group of 25 teachers, 20 engineers, 18 doctors and 12 salesmen visited a fair and spent Rs 13,300 altogether. It was found that 5 teachers spent as much as 4 engineers, 12 engineers spent as much as 9 doctors and 6 doctors spent as much as 8 salesmen. If every person in a group spent the same amount, find the amount spent by each engineer.