DS: Numbers

Question

Easy One;)

banerjeea_98 · Answer

"C"

is 10XY even ?

state 1....x+y+7 = even....x+y = odd......so x = 1/2 and Y = 1/2...XY is not even an integer.....but if X = 2 and Y = 1...10XY = 20...ans is YES...insuff

state 2....x-y = odd....x = 3/2 and y = 1/2 ....XY is not even an integer...insuff

combine

x-y = odd
x+y = odd

2x = even and 2y = even.....so both X and Y are integers, can be odd or even....but no matter what 10XY is always even as long as XY are integers as 10 has one 2 in it...suff

ywilfred · Answer

I find this question strange.
A product will be even as long as it has one even number invovled.

E.g. 2*3 = 6
5*2 = 10
10*3 = 30 

So 2*5*x*y will always be even, no matter what x or y are.

Antmavel · Answer

No, it is not said that x or y have to be integers. If x=3/2 and y=1, 2*5*3/2*1 = 15 which is an odd number :wink:

mirhaque · Answer

is 10XY even ?

S1=>x-y = odd
s2=>x+y = odd

2x = even 
2y = even

C

HongHu · Answer

I think it is good that people look at the question and post their solutions and answers first without reading other people's posts. However, after you have done this I suggest you go back to read other posts. Sometimes you can learn a lot from how others tackle a question. Don't just wait for OA and then say "Oh I was right" or "Darn wrong again" without really think why and how. This thread for example, do we really need to have the OA to answer some of your questions and to verify your answers?

Folaa3 · Answer

I didn't put into consideration that x and y are not neccesarily integers. Good catch baneer

DS: Numbers

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