Let assume that first angle is 2x Second angle is 3x Third angle is 5x ⇒ 2x + 3x + 5x = 180° ⇒ 10x = 180° ⇒ x = 18° So, The first angle = 2 × 18° = 36° The second angle = 3 × 18° = 54° The third angle = 5 × 18° = 90° ∴ The sum of smallest and largest angles of the triangle = 36° + 90° = 126° The correct option is 2 i.e. 126°