SSC CGL 2024 PYQ — Question 72

SSC CGL - 25 Sep 2024 - Shift 3 • Quantitative Aptitude • Q72

If a2 + b2 = 148 and ab = 54, then find the value of a+ba−b\frac{a+b}{a-b}.

Show answer & explanation

Correct answer: A

Explanation

The correct answer is option 1 i.e. 810\frac{8}{\sqrt{10}}.

(a - b)2 = a2 + b2 - 2ab = 148 - 2(54) = 148 - 108 = 40

⇒ a - b =40\sqrt{40} = 210\sqrt{10}

Also, (a + b)2 = a2 + b2 + 2ab = 148 + 2(54) = 148 + 108 = 256

⇒ a + b =256\sqrt{256 } = 16

Now, a+ba−b\frac{a+b}{a-b} = 16210\frac{16}{2\sqrt{10}} = 810\frac{8}{\sqrt{10}}