<PRE><B>Question 774509</B>
70 percent of the 100 students in a middle school class cafeteria bought their lunch.
 Some of the students that bought their lunch leave the cafeteria to attend an assembly. Now only 60 percent of the remaining students bought their lunch.
How many students are remaining?
:
Let x = number of student that left
:
{{{(70-x)/(100-x)}}} = .6
multiply by (100-x)
70 - x = .6(100 - x)
70 - x = 60 - .6x
70 - 60 = x - .6x
10 = .4x
x = 10/.4
x = 25 students left
therefore
100-25 = 75 students remain
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