SOLUTION: The average of 10 students’ test scores was 69. Three students scored 80,60, and 40 respectively. Three other students scored 90, and two students scored 50. The other two students

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Question 319490: The average of 10 students’ test scores was 69. Three students scored 80,60, and 40 respectively. Three other students scored 90, and two students scored 50. The other two students received the same score. What were their scores?
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
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The average of 10 students’ test scores was 69.
Three students scored 80,60, and 40 respectively.
Three other students scored 90, and two students scored 50.
The other two students received the same score. What were their scores?
:
Let 2x = the two unknown grades
:
Write an equation from the given information:
%2880%2B60%2B40%2B3%2890%29%2B2%2850%29%2B2x%29%2F10 = 69
Multiply both sides by 10
80+60+40+270+100+2x = 690
:
2x + 550 = 690
:
2x = 690 - 550
:
2x = 140
x = 140%2F2
x = 70 are the unknown scores