goyalsau wrote:If y is an integer, then the least possible value of ||23 - 5y|| is
3
1
2
4
5
[spoiler]OA is 3
I think it should be 2, 23-25 = 2
[/spoiler]
Awesome!! Great Question. I would have gone for 2 at first glance. If the source is authentic then here are my 2 cents to match the answer

:
What is |x|?
When x < 0: |x| = -x
When x > 0: |x| = x
So Break it and take the first absolute
when (23-5y) < 0: |23 - 5y| = -(23-5y) Now if u take y = 5 u will get 4 and if you take y = 4 u will get -3 ....(a)
when (23-5y) > 0: |23 - 5y| = (23-5y) Now if u take y = 5 u will get -2 and if you take y = 4 u will get 3 .....(b)
We cannot take 4 as an answer in (a) as (23-5y) < 0. So -3.
We cannot take -2 as an answer in (b) as (23-5y) > 0. So 3.
Now try the second absolute value on -3 or 3. Either case the least is 3.
I think the key here is not to consolidate both ABS at a time
Hope I am correct....

Last edited by shovan85 on Tue Oct 05, 2010 5:54 am, edited 1 time in total.