Banking Quantitative Aptitude Sample Paper Quantitative Aptitude Sample Paper-36

For any two numbers \[m,\,\,n;\,\,(m+n):(m-n):\]\[mn=7:1:60.\] Find the value of

A) 4 : 3

B) 8 : 6

C) 3 : 4

D) 7 : 8

Correct Answer: C

Solution :

\[\frac{m+n}{m-n}=\frac{7x}{x}\]

\[\Rightarrow \]\[\frac{m}{n}=\frac{4x}{3x}\] [by componendo and dividendo]

Now, \[mn=4x\times 3x=12{{x}^{2}}\]

But \[mn=60x\]

\[\Rightarrow \] \[60x=12{{x}^{2}}\]\[\Rightarrow \]\[x=5\]

\[\therefore \] \[\frac{1}{m}:\frac{1}{n}=\frac{1}{20}:\frac{1}{15}=3:4\]