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sanjoo
Alice has x stamps and Thomas has y stamps, where x and y are positive integers. The ratio of x to y is 7 to 3. If Alice gives Thomas z stamps, where z is a positive integer and z < x, and no other changes take place in the numbers of stamps that Alice and Thomas have, then the ratio of the number of stamps that Alice has to the number of stamps that Thomas has will become 7 to 8. Which of the following equations correctly describes z in terms of x?

A. z = x/3
B. z = x/2
C. z = 2x/3
D. z = 3x/2
E. z = 3x

Given that
X/Y = 7/3 --------- ( 1 )

( X - Z ) / ( Y + Z ) = 7/8
=> ( X - Z ) ( 3X/7 + Z ) = 7/8 ( from equation 1 )
=> 8X - 8Z = 3X + 7Z
=> 5X = 15Z
=> Z = X/3

Answer : A
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Alice has x stamps and Thomas has y stamps, where x and y are positive integers. The ratio of x to y is 7 to 3. If Alice gives Thomas z stamps, where z is a positive integer and z < x, and no other changes take place in the numbers of stamps that Alice and Thomas have, then the ratio of the number of stamps that Alice has to the number of stamps that Thomas has will become 7 to 8. Which of the following equations correctly describes z in terms of x?

A) z = x/3
B) z = x/2
C) z = 2x/3
D) z = 3x/2
E) z = 3x
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Carlgrc
Alice has x stamps and Thomas has y stamps, where x and y are positive integers. The ratio of x to y is 7 to 3. If Alice gives Thomas z stamps, where z is a positive integer and z < x, and no other changes take place in the numbers of stamps that Alice and Thomas have, then the ratio of the number of stamps that Alice has to the number of stamps that Thomas has will become 7 to 8. Which of the following equations correctly describes z in terms of x?

A) z = x/3
B) z = x/2
C) z = 2x/3
D) z = 3x/2
E) z = 3x


X/y=7/3....y=3x/7
Also (x-z)/(y+z)=7/8
8x-8z=7y+7z......8x-7y=15z
Substitute y = 3x/7
So 8x-7*3x/7=15z......8x-3x=15z.....5x=15z
Z=X/3

A
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x/y = 7/3 hence, 7y = 3x

(x-z)/(y+z) = 7/8
8x - 8z = 7y + 7z = 3x + 7z
5x = 15z
z = x/3
so A
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Carlgrc
Alice has x stamps and Thomas has y stamps, where x and y are positive integers. The ratio of x to y is 7 to 3. If Alice gives Thomas z stamps, where z is a positive integer and z < x, and no other changes take place in the numbers of stamps that Alice and Thomas have, then the ratio of the number of stamps that Alice has to the number of stamps that Thomas has will become 7 to 8. Which of the following equations correctly describes z in terms of x?

A) z = x/3
B) z = x/2
C) z = 2x/3
D) z = 3x/2
E) z = 3x

Merging topics. Please search before posting a question.
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Alice has x stamps and Thomas has y stamps, where x and y are positive integers. The ratio of x to y is 7 to 3. If Alice gives Thomas z stamps, where z is a positive integer and z < x, and no other changes take place in the numbers of stamps that Alice and Thomas have, then the ratio of the number of stamps that Alice has to the number of stamps that Thomas has will become 7 to 8. Which of the following equations correctly describes z in terms of x?

A. z = x/3
B. z = x/2
C. z = 2x/3
D. z = 3x/2
E. z = 3x

3x = 7y
And, 8*(x - z) = 7*(y + z)
or, 8x - 8z = 7y + 7z
or, z = 8x - 7y /15 =(8x - 7*3x/7)/15 = 5x/15 = x/3.
A is the answer.
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