Banking Quantitative Aptitude Sample Paper Quantitative Aptitude Sample Paper-43

When x is subtracted from the numbers 9, 15 and 27, the remainders are in continued proportion. What is the value of x?                                                                                                            [IBPS (PO/MT) CWE 2014]

A) 8

B) 6

C) 4

D) 5

E) None of these

Correct Answer: E

Solution :

Here, \[9-x:15-x::15-x:27-x\] are in continued proportion.

\[\therefore \]Product of extremes = Product of means

\[{{(15-x)}^{2}}=(9-x)(27-x)\]

\[\Rightarrow \]\[225-30x+{{x}^{2}}=243+{{x}^{2}}-36x\]

\[\Rightarrow \]\[6x=243-225\]\[\Rightarrow \]\[6x=18\]\[\Rightarrow \]\[x=3\]

\[\therefore \]Numbers become, \[9-x=9-3=6\]

\[15-x=15-3=12\]

and \[27-x=27-3=24\]

Hence, 6: 12: 24 are in continued proportion on subtracting 3 from 9, 15 and 27.