The probability a student in a school wears glasses is 3/7. There are 164 students who DON'T wear glasses. Find the number that wear glasses.
The probability they wear glasses is 3/7, which means the probability they don't is 1-3/7=4/7. This means 164 students make up 4/7 of the school. To find the number that wear glasses we need to find how many students in 3/7 of the school. First find 1/7, which is 164 divided by 4 (as 1/7 is 4/7 divided by 4), which is 41. Then the total number that wear glasses (3/7) is 41x3=123
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