Let the number of 25-cents, 50-cents and 1$ be a,B, and c respectively.
So 25a+50b+100c=500....a+2b+4c=20
Statements..
I..c=b>a
So substitute b as c...a+2c+4c=20...a+6c=20..
Now c>a...so if a=1, c can be 3... possible
If a=2, no value of c satisfies c>a
So a=2, b=c=3
Sufficient

II.. some error in statement II
Now after editing the second statement as The number of 25 cents coins is 2/3 of the number of 50 cent coins.
a+2b+4c=20 and \(a=\frac{2b}{3}\)
thus \(\frac{2b}{3}+2b+4c=20......8b+12c=60......2b+3c=15\)
Possible values b=c=3, and a=2..
OR b=6, c=1, and a = 4..
so different possibilities
Insufficient

A
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So i went for A, Now when i read the 2nd statement, its not clear what it meant by 23 of the number of 50 cent coins.

Statement 1, can be solved very easily
x = number of 25 cents, y number of 50 cents and z number of 1 dollar

0.25 x + 0.50 y + 1 z = 5.00
25x + 50 y + 100z = 500

Number of $1 coins = number of 50 cent coins > number of 25 cent coins.
y=z > x, can only be true when you take values as y=z= 3 and x =2

50 + 150 + 300 = 500.

Sufficient.

OP do share your thoughts.
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II edited

Hi,

still the question is required to be edited, it is not the number of 1$ coins 2/3 of number of 50 cents coin because statement I gives you both as equal and you cannot have different information from the two statements.
It should be the number of 25 cents coins is 2/3 of number of 50 cents coin.

I am editing it accordingly
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Thank you "chetan2u"


II edited[/quote]


Hi,

still the question is required to be edited, it is not the number of 1$ coins 2/3 of number of 50 cents coin because statement I gives you both as equal and you cannot have different information from the two statements.
It should be the number of 25 cents coins is 2/3 of number of 50 cents coin.

I am editing it accordingly[/quote]

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