Banking Quantitative Aptitude Sample Paper Quantitative Aptitude Sample Paper-26

The average of three consecutive odd numbers is 12 more than one-third of the first of these numbers. What is last of the three numbers?                                                                                                                       [SSC (CQL) 2011]

A) 15

B) 17

C) 19

D) 21

Correct Answer: C

Solution :

Let the smallest number be \[(2x-1).\]Then, consecutive number are \[(2x+1),\]\[(2x+3).\]

According to the question,

\[\frac{(2x-1)+(2x+1)+(2x+3)}{3}=\left( \frac{2x-1}{3} \right)+12\]

\[\Rightarrow \] \[2x+1=\frac{2x-1+36}{3}\]

\[\Rightarrow \] \[6x+3=2x+36-1\]

\[\Rightarrow \] \[4x=32\]\[\Rightarrow \]\[x=\frac{32}{4}=8\]

\[\therefore \]Third number \[=(2x+3)=(2\times 8+3)=19\]