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Question 1189278:  A jar contains red, white, and yellow candy pieces  
in the ratio 9:5:4 of respectively. When 7 pieces of red  
candy and 5 pieces of white candy are removed  
from the jar and 3 pieces of yellow candy are added,  
the ratio of red to white to yellow becomes 4: 2: 3.  
If the jar contains only these three colors of candy,  
how many pieces were originally in the jar? 
 
 Answer by ikleyn(52903)      (Show Source): 
You can  put this solution on YOUR website! . 
A jar contains red, white, and yellow candy pieces 
in the ratio 9:5:4 of respectively. When 7 pieces of red 
candy and 5 pieces of white candy are removed 
from the jar and 3 pieces of yellow candy are added, 
the ratio of red to white to yellow becomes 4: 2: 3. 
If the jar contains only these three colors of candy, 
how many pieces were originally in the jar? 
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From the condition, we can write
    R = 9x,  W = 5x,  Y = 4x
for the number of red, white and yellow candy pieces in the jar originally,
where x is the common factor (multiplier).
According to the condition, we have this proportion
      =   = 2,
which gives
    9x - 7 = 2*(5x-5)
    9x - 7 = 10x - 10
    10 - 7 = 10x - 9x
       x = 3.
At this point, we can just answer the problem's question: R = 27,  W = 15,  Y = 12.
The last condition is EXCESSIVE, and we should check that it does not contradict to 
(is consistent with) the answer.
CHECK.  After manipulations, the jar contains  R = 20,  W = 10  and Y = 15 candy pieces,
       so this proportionality  4 : 2 : 3  is held for the final state.
 
Solved and explained.
 
 
 
 
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