We know that r+s>2t, so r-t>t-syalanand wrote:If r + s > 2t, is r > t ?
(1) t > s
(2) r > s
from (1): t>s => t-s>0 => r-t>t-s>0 => r>t so (1) alone is sufficient.
from (2): r>s => r+s>2s.............(a) and we have r+s>2t............(b)
(a)+(b) => 2r+2s>2s+2t => r>t, so (2) alone is also sufficient.
My answer is (D).
