When y^2 is divided by 6, the remainder is r. What is the remainder when the positive integer y is divided by 6?
(1) y=15
Straight answer-- 15 divided by 6 will give remainder 3
Suff
(2) r=3
SO y^2 divided by 6 gives 3 as remainder, so y^2=6k+3=3(2k+1)
Hence y^2 is surely a multiple of 3 and odd, as y is a positive integer, y will also be a multiple of 3 and odd..
ANY odd multiple of 3 will always leave 3 as the remainder when divided by 6.
Suff
D
(1) y=15
Straight answer-- 15 divided by 6 will give remainder 3
Suff
(2) r=3
SO y^2 divided by 6 gives 3 as remainder, so y^2=6k+3=3(2k+1)
Hence y^2 is surely a multiple of 3 and odd, as y is a positive integer, y will also be a multiple of 3 and odd..
ANY odd multiple of 3 will always leave 3 as the remainder when divided by 6.
Suff
D
