Lines PQ and RS intersect at O, ∠POR: ∠ROQ = 5:7, then ∠POS is equal to
90o
100o
105o
130o
∠POR = 5x, ∠ROQ = 7x. They form linear pair. Hence, 5x + 7x = 180o => x = 15o Then ∠ROQ = 105o∠POS = ∠ROQ = 105o (vertically opposite angles)