SOLUTION: [ the average age of a class of 21 students is 14 years 3 months, IF the oldest student is not counted in, the average drops to 14 years 2 months. calculate the age of the oldest s

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Question 821492: [ the average age of a class of 21 students is 14 years 3 months, IF the oldest student is not counted in, the average drops to 14 years 2 months. calculate the age of the oldest student ]
Answer by TimothyLamb(4379) About Me  (Show Source):
You can put this solution on YOUR website!
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(x + y)/21 = 171
(1/21)x + (1/21)y = 171
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x/20 = 170
(1/20)x = 170
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(1/21)x + (1/21)y = 171
(1/20)x = 170
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(0.047619)x + (0.047619)y = 171
(0.05)x = 170
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0.047619x + 0.047619y = 171
0.05x = 170
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copy and paste the above standard form linear equations in to this solver:
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x= 3400
y= 191.003591
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x= 3400/20/12 = average age of the younger students = 14.2 years
y= 191.003591/12 = age of the oldest student = 15.916966 years
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answer:
age of the oldest student = 15.9 years = 15 years and 11 months
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