SOLUTION: Please help me solve this question. The average of five numbers is 50. The average of four of the numbers is 40. What is the fifth number?

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Question 924157: Please help me solve this question. The average of five numbers is 50. The average of four of the numbers is 40. What is the fifth number?
Answer by TimothyLamb(4379) About Me  (Show Source):
You can put this solution on YOUR website!
x = sum of all 5 numbers
y = sum of first 4 numbers
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x/5 = 50
y/4 = 40
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x = 50*5
y = 40*4
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x = 250
y = 160
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answer:
5th number = x - y
5th number = 250 - 160
5th number = 90
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