Integer

[deepoe]

If p is an integer, is ( p/ 18 ) an integer?

1. ( 5p / 18 ) is an integer.
2. ( 6p / 18 ) is an integer.


I don't undestand why statement 1 is sufficient and 2 not?

[thephoenix]

S1 is suff and S2 is not for the following reasons

S1) if its true then p can be anything------->18,36.....multiple of 18

for all the value mentioned above p/18 is an int

S) =p/3 and it can be int for all p=3,6,9,12,15,18,......multiple of 3

and as we can see from s2 that if p=3 s2 is true but the p/18 is not an int
and for p=18 bth the s2 is true and p/18 is int
two possibilties and hence insuff..

HTH