SOLUTION: In a survey of 100 students, the numbers taking various courses were found to be English, 70; mathematics, 45; chemistry, 60; English and mathematics, 30; English and chemistry, 38
Question 1100288: In a survey of 100 students, the numbers taking various courses were found to be English, 70; mathematics, 45; chemistry, 60; English and mathematics, 30; English and chemistry, 38; mathematics and chemistry, 36; and courses in all three areas, 23. Found 2 solutions by ikleyn, richwmiller:Answer by ikleyn(52781) (Show Source):
Then the number of students of those 100 surveyed who took at least one course was
70 + 45 + 60 - (30+38+36) + 23 = 94,
and the number of those who took NO ONE of these courses was 100-94 = 6.
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It is a beautiful problem, and I like to explain it to students in all details, but this time I was partly upset
by not seeing a question in your post . . .