SSC CGL 2023 PYQ — Question 56

The correct answer is Option 1 i.e. 12.

A = 22.5° then, 2A = 45°

⇒ 10$\sqrt2$sin2A - 7$\sqrt2$cos2A + 9tan2A

⇒ 10$\sqrt2$sin45° - 7$\sqrt2$cos45° + 9tan45°

⇒ $10\sqrt{2} \times {1\over \sqrt2}- 7 \sqrt{2} \times{1\over\sqrt2} + 9 \times1$

⇒ 10 - 7 + 9 = 19 - 7 = 12