Question 174609
Sharing cost. The members of a flying club plan to share equally the cost of a $200,000 airplane. The members want to find five more people to join the club so that the cost per person will decrease by $2000. How many members are currently in the club?
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Let original # in the club be "x"; average share = 200,000/x dollars
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After finding 5 more members "x+5"; average share = 200,000/(x+5) dollars
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Equation:
original average - new average = 2000
200,000/x - 200,000/(x+5) = 2000

Divide thru by 2000 to get:

100/x - 100/(x+5) = 1

100(x+5) - 100x = x^2+5x

500 = x^2+5x
x^2 + 5x -500 = 0

(x-20)(x+25) = 0

x = 20 (original # of members
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Ceers,
Stan H.