SOLUTION: My son has a math worksheet that he needs to score at least 90% on. It has 12 problems on it. How do we figure how many problems he has to get right in order to score at least 90%?

Question 522491: My son has a math worksheet that he needs to score at least 90% on. It has 12 problems on it. How do we figure how many problems he has to get right in order to score at least 90%?
Found 3 solutions by scott8148, jim_thompson5910, oberobic:
Answer by scott8148(6628)   (Show Source): You can put this solution on YOUR website!
x / 12 = .9

x = 10.8
Answer by jim_thompson5910(35256)   (Show Source): You can put this solution on YOUR website!
x/12 = 90/100

x/12 = 0.9

x = 0.9*12

x = 10.8

So he needs to get 11 problems correct (you round up to the nearest whole number)

If you need more help, email me at jim_thompson5910@hotmail.com

Also, please consider visiting my website: http://www.freewebs.com/jimthompson5910/home.html and making a donation. Thank you

Jim

Answer by oberobic(2304)   (Show Source): You can put this solution on YOUR website!
Assuming there are a total of 100 points, 100/12 = 8 1/3 points per answer.
.
To score at least 90, means 90 or more.
.
x = number of correct answers
.
100/12*x >= 90
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100x = 1080
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x = 10.8
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Assuming you can only get full credit for an answer or no credit, then your son must get at least 11 of the 12 questions right to have a score of 90% or higher.
.
Done.
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