SOLUTION: The average a,b, and c is 15. The average of a and b is 18. What is the value of c?
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Question 835590: The average a,b, and c is 15. The average of a and b is 18. What is the value of c?
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
The average a,b, and c is 15. The average of a and b is 18. What is the value of c?
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Equations:
(a+b)/2 = 18
So, a+b = 36
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(a+b+c)/3 = 15
So, a+b+c = 45
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Substitute for "a+b" and solve for "c":
36 + c = 45
c = 9
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Cheers,
Stan H.
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