SOLUTION: On a recent exam, 9/10 of the class received 70% or higher. Of the students receiving 70% or higher, 1/4 received 90%. What fraction of all students received 90% or higher.

Question 990181: On a recent exam, 9/10 of the class received 70% or higher. Of the students receiving 70% or higher, 1/4 received 90%. What fraction of all students received 90% or higher.
Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!

No way to tell. Of the 90% who scored higher than 70%, 1/4 scored 90%. That means that 3/4 of the 90% scored something different than 90%, but there is nothing to indicate what part of that 3/4 scored less than 90% and what part scored more than 90%.

John

My calculator said it, I believe it, that settles it

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