SOLUTION: If someone missed 9 problems and got a 60%, how many questions we're on the test?

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Question 903285: If someone missed 9 problems and got a 60%, how many questions we're on the test?
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
x = number of problems


missed 9 problems

got x-9 problems correct


(# correct)/(# total) = percent correct

(x-9)/x = 0.6

x-9 = 0.6x

-9 = 0.6x - x

-9 = -0.4x

-0.4x = -9

x = -9/(-0.4)

x = 22.5

Round up to get 23. So there are 23 problems total (23-9 = 14 are correct)