SOLUTION: A bag contains some silver balls and golden balls. If you remove one silver ball from the bag, 1/7 of the remaining balls in the bag are silver. If you remove 2 GOLDEN balls from t
Question 1006469: A bag contains some silver balls and golden balls. If you remove one silver ball from the bag, 1/7 of the remaining balls in the bag are silver. If you remove 2 GOLDEN balls from the bag, 1/5 of the remaining balls in the bag are silver. How many balls are there in the bag at first?
Please have a clear explanation, thanks! Found 2 solutions by ikleyn, josmiceli:Answer by ikleyn(52781) (Show Source): You can put this solution on YOUR website! .
Mathematical model is the system of these two equations:
= ,
= .
where s is the number of silver balls and g is the number of golden balls in the bag initially.
Could you solve it yourself?
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website! Let = number of golden balls in bag at first
Let = number of silver balls in bag at first = total number of balls in bag at first
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given:
(1)
( note that are the number of balls remaining in bag )
(2)
( are number of balls remaining in bag )
--------------------------
Multiply both sides of (1) by
(1)
(1)
--------------------
Multiply both sides of (2) by
(2)
(2)
------------------
Subtract (1) from (2)
(2)
(1)
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and
(2)
(2)
(2)
(2)
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There are 22 balls in the bag at first
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check the answer:
Remove 1 silver ball
There are silver balls left
There are total balls left
OK
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Remove 2 golden balls
There are golden balls left
There are total balls left
OK