1) Simplify : $\sqrt{\left(12.1^{2}-8.1^{2}\right)\div \left(0.25^{2}+\left(0.25\right) \left(19.95\right)\right)}$ A) 4 B) 3.5 C) 2.45 D) 3.7 Answer: Option AExplanation:Given exp = $ \sqrt{\frac{(12.1+8.1)(12.1-8.1)}{(0.25)(0.25+19.95)}}$$= \sqrt{\frac{ 20.2\times 4}{ 0.25\times 20.2}}$$= \sqrt{\frac{ 4}{ 0.25 }}$$= \sqrt{\frac{ 400}{ 25}}$$= \sqrt{16}$= 4
