67) Is n divisible by 10?

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Source: — Data Sufficiency |

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by gmatmachoman » Wed May 12, 2010 4:49 am
ern5231 wrote:N = x + y + z . Is N divisible by 10?
(1) x + z is a multiple of 10
(2) y is a multiple of 10

i think the answer is C. what is your take?
st 1 : doesnt say abt Y

Y can be zero or anything. SO insufficient

St 2:

Doesnt say abt x,z

Combining

YES!

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by [email protected] » Thu May 13, 2010 2:30 pm
gmatmachoman wrote:
ern5231 wrote:N = x + y + z . Is N divisible by 10?
(1) x + z is a multiple of 10
(2) y is a multiple of 10

i think the answer is C. what is your take?
st 1 : doesnt say abt Y

Y can be zero or anything. SO insufficient

St 2:

Doesnt say abt x,z

Combining

YES!
:roll:

1. x+z = 10r
2. y = 10q

combine the two statements:

x+y+z = N =10r+10q
N = 10(r+q)

ANSWER (C).

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by analyst218 » Thu May 13, 2010 2:50 pm
ern5231 wrote:N = x + y + z . Is N divisible by 10?
(1) x + z is a multiple of 10
(2) y is a multiple of 10

i think the answer is C. what is your take?
C.
you need to know whether X , Y, and Z are all divisible by 10 .
only then you know the sum is divisible by 10.
1) X+Z is divisible by 10. Y could be 1 or 10 INSUFF
2) Y is divisible by 10. X+Z could be anything INSUFF.
combined, you know that (X+Z) + Y is divisble by 10.