NIELIT 2016 MAR Scientist D: 39

Question

Look carefully for the pattern, and then choose which pair of numbers comes next

$17 \: 17 \: 34 \: 20 \: 20 \: 31 \: 23$

• A. $26 \: 23$
• B. $23 \: 33$
• C. $27 \: 28$
• D. $23 \: 28$

Answer 1

$\textrm{This is an alternating subtraction series with repetition. There are two different patterns here.}$

. $\textrm{In the first, a number repeats itself; then 3 is added to that number to arrive at the next number, which also repeats.}$

$\textrm{This gives the series 17, 17, 20, 20, 23,23 and so on.}$

$\textrm{Every third number follows a second pattern, in which 3 is subtracted from each number to arrive at the next: 34, 31, 28}$.

$\textrm{First Series: $17+3=20$,$20+3=23$}$

$\textrm{Second series: $34-3=31$,$31-3=28$}$

$\textrm{Option D}$