Question 949402
The ratio of students who wear glasses to the total class is 2:5.  If there are 25 students who don't wear glasses, how many students are n the class?
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n = # of students total
w = # without glasses = 25
n-25 = # with glasses
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n-25:n = 2:5
or,
(n-25)/n = 2/5  (same thing)
5(n-25) = 2n
5n - 125 = 2n
3n = 125
n = 125/3
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There's no integer solution.
If n = 41:
16/41 <> 2:5  (2:5 = 16:40)
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If n = 42:
17:42 = 0.40476, not 2:5 which is 0.4