Math  Need help please
posted by Chris .
There are 1,800 students at a high school. Of the students who have smoked at least one cigarette in the last month, fiveeighteenths are twelfth graders. Thirtyfive percent of the remaining students are eleventh graders, and the rest are in the ninth and tenth grades. If there are 169 students in the ninth and tenth grades who have smoked at least one cigarette in the last month, how many students in all have smoked at least one cigarette in the last month?
260 students
360 students
50 delegates
35 delegates
These choices do not make sense because 5/18 of 1800 is 500 by itself ???

5/18 of the total smokers are in 12th grade.
You need to find how many smokers there are. 
That's not true.
See what it says
Of the students who have smoked at least one cigarette in the last month, fiveeighteenths are twelfth graders.
That equals 500 more than all the choices given 
4+_3=_5

7x+3.=