Question 1199701: the ratio of the number of pupils who wear glasses to the total number of pupils in the class is 2:5, what is the ratio of pupils who wear glasses to those who do not if 5 of the pupils who did not wear glasses now do?
Found 4 solutions by greenestamps, math_tutor2020, ikleyn, josgarithmetic:
Answer by greenestamps(13200)   (Show Source):
You can put this solution on YOUR website!
Be polite, using clear language and appropriate punctuation, when you post your question. It should not be our job to try to figure out exactly what your questions are.
Re-post....
Answer by math_tutor2020(3817)  (Show Source):
You can put this solution on YOUR website!
x = a positive whole number from the set {1,2,3,4,...}
2x = number of people who wear glasses
5x = number of people in class
This forms the ratio 2x:5x and it reduces fully to 2:5.
If 2x people wear glasses out of 5x total, then 5x-2x = 3x people do not wear glasses.
We have 5 people who initially didn't wear glasses, but now do.
The glasses count goes from 2x to 2x+5
The non-glasses count goes from 3x to 3x-5
We then get to the ratio glasses:nonGlasses = (2x+5):(3x-5)
Unfortunately there isn't enough information to determine x.
This means we cannot determine a numeric ratio based on the current given information.
It seems like your question is incomplete.
Double-check to make sure you typed in the full problem.
Answer by ikleyn(52781)  (Show Source):
Answer by josgarithmetic(39617) (Show Source):
You can put this solution on YOUR website! 5n, number of pupils in class
2n, how many wear glasses
3n, how many do not wear glasses
The change - five pupils who did not wear glasses now do wear glasses.
5n pupils in class
2n+5 who now do wear glasses
3n-5 who now do not wear them
The question: what is the ratio of pupils who wear glasses to those who do not
if 5 of the pupils who did not wear glasses now do?
That ratio is  .
maybe about the most or best that can be done.
The class must be of at least 10 students for the description to be meaningful.
|
|
|
