and y + z = x/k

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and y + z = x/k

by sanju09 » Sat Jun 19, 2010 2:16 am
If x, y and z are positive numbers such that 5 x = y/4, y/4 = z/5 and y + z = x/k, what is the value of k?
(A) 1/45
(B) 1/25
(C) 1/5
(D) ½
(E) 5/4
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by selango » Sat Jun 19, 2010 2:21 am
5x=y/4

y/4=z/5

-->5x=z/5

y=20x and z=25x

y+z=x/k

45x=x/k

k=1/45

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by amising6 » Sat Jun 19, 2010 2:31 am
sanju09 wrote:If x, y and z are positive numbers such that 5 x = y/4, y/4 = z/5 and y + z = x/k, what is the value of k?
(A) 1/45
(B) 1/25
(C) 1/5
(D) ½
(E) 5/4
5 x = y/4, y/4 = z/5 =l
x=l/5
y=4l
z=5l
then
y + z = x/k
4l+5l=(l/5)/k
9l=l/5k
k=1/45
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