Quantitative Aptitude Ques 1756

Question: Directions: In each of these questions, two equations I and II are given. You have to solve both the equations and give answer. [IBPS (PO) 2013]

I. $ x^{2}-24x+144=0 $
II. $ y^{2}-26y+169=0 $

Options:

A) If $ x<y $

B) If $ x>y $

C) If $ x=y $

D) If $ x\ge y $

E) If $ x\le y $ or no relationship can be established between x and y

Show Answer

Answer:

Correct Answer: A

Solution:

  • I. $ x^{2}-24x+144=0 $

$ \Rightarrow $ $ x^{2}-12x-12x+144=0 $

$ \Rightarrow $ $ x(x-12)-12(x-12)=0 $

$ \Rightarrow $ $ (x-12)(x-12)=0 $

$ \Rightarrow $ $ {{(x-12)}^{2}}=0 $

$ \therefore $ $ x=12 $ II. $ y^{2}-26y+169=0 $

$ \Rightarrow $ $ y^{2}-13y-13y+169=0 $

$ \Rightarrow $ $ y(y-13)-13(y-13)=0 $

$ \Rightarrow $ $ {{(y-13)}^{2}}=0 $

$ \therefore $ $ y=13 $ Hence, $ y>x $ Alternate Method I. $ x^{2}-24x+144=0 $

$ \Rightarrow $ $ x^{2}-2(12)(x)+{{(12)}^{2}}=0 $

$ \Rightarrow $ $ {{(x-12)}^{2}}=0 $

$ \therefore $ $ x=12 $ II. $ y^{2}-26y+169=0 $

$ \Rightarrow $ $ y^{2}-2(13)(y)+{{(13)}^{2}}=0 $

$ \Rightarrow $ $ {{(y-13)}^{2}}=0 $

$ \therefore $ $ y=13 $ Hence, $ y>x $