SOLUTION: John bought some vases for $1344. 5 of them were broken during delivery. He then sold the rest of the vases each at $80 more than its original cost. He made no overall gain or loss

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Question 1030109: John bought some vases for $1344. 5 of them were broken during delivery. He then sold the rest of the vases each at $80 more than its original cost. He made no overall gain or loss. Find the number of vases John bought.
Answer by ankor@dixie-net.com(22740)   (Show Source): You can put this solution on YOUR website!
John bought some vases for $1344.
5 of them were broken during delivery.
He then sold the rest of the vases each at $80 more than its original cost.
He made no overall gain or loss.
Find the number of vases John bought.
:
let v = no. of vases he bought
then, since 5 were broken;
(v-5) = no. of vases he sold
:
= his cost for each vase
and
+ 80 = selling price of each vase
:
No overall gain, therefore
(v-5)*(+80) = 1344
(+80) =
=
cross multiply
1344v = (1344+80v)(v-5)
FOIL the right side
1344v = 1344v - 6720 + 80v^2 - 400v
Subtract 1344v from both sides, form a quadratic equation
0 = 80v^2 - 400v - 6720
Simplify, divide equation by 80
v^2 - 5v - 84 = 0
Factors to
(v-12)(v+7) = 0
The positive solution
v = 12 vases purchased originally
:
:
See if that works out
1344/12 = $112 each
7(112+80) = $1344, total return on 7 vases sold

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