Number System Ques 17
Question
The average of a series of four consecutive even numbers $\left(S_{1}\right)$ is 31 . If the lowest number of another series of five consecutive odd numbers $\left(S_{2}\right)$ is 13 less than the 2nd highest number of $S_{1}$, what is the difference between the highest number of $S_{1}$ and that of $S_{2}$ ?
(1) 7
(2) 13
(3) 5
(4) 9
(5) 11
(IBPS RRBs Officer CWE (Prelim Exam) 11.08.2018)
Show Answer
Answer: (1)
Solution: (1)
4 consecutive even numbers
$\Rightarrow x, x+2, x+4$, and $x+6$.
$\therefore x+x+2+x+4+x+6$ $=31 \times 4$
$\Rightarrow 4 x+12=124$
$\Rightarrow 4(x+3)=124$
$\Rightarrow x+3=\frac{124}{4}=31$
$\Rightarrow x=31-3=28$
$\therefore$ Second largest even number $=x+4=28+4=32$
$\therefore$ First number of $S_{2}$ $=32-13=19$
$\therefore$ Largest number of $S_{2}$ $=19+8=27$
Largest number of $S_{1}=34$
Required difference $=34-27=7$
BETA
