SOLUTION: JON wants a grade of 80% in Science. He currently has two test scores. If his scores are 85% and 70%, what does he need to earn on the last test? Assume there are no other grades.

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Question 916686: JON wants a grade of 80% in Science. He currently has two test scores. If his scores are 85% and 70%, what does he need to earn on the last test? Assume there are no other grades.
Found 2 solutions by josmiceli, jim_thompson5910:
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+%28+85+%2B+70+%2B+x+%29+%2F+3+=+80+
+85+%2B+70+%2B+x+=+240+
+155+%2B+x+=+240+
+x+=+85+
He needs an 85% on the 3rd test
to get 80% for the course

Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
x = score as a percentage on last test


(85% + 70% + x)/3 = 80%

85% + 70% + x = 3*80%

85% + 70% + x = 240%

155% + x = 240%

x = 240% - 155%

x = 85%


He needs a 85% on the last test.


Let me know if you need more help or if you need me to explain a step in more detail.
Feel free to email me at jim_thompson5910@hotmail.com
or you can visit my website here: http://www.freewebs.com/jimthompson5910/home.html

Thanks,

Jim