In which of the following number, the pairs of numbers which have as many numbers between them (both forward and backward) as in the number series is not a prime number?

Solution

In option 'A', given number: ‘573681723’. There are 4 number pairs (37, 23, 26 and 35) in the given number (both forward and backward), which have as many digits between them as in the number series. In option 'B', given number: ‘162871234’. There are 8 number pairs (68, 12, 13, 14, 23, 24, 34 and 78) in the given number (both forward and backward), which have as many digits between them as in the number series. In option 'C', given number: ‘264581623’. There are 6 number pairs (24, 25, 45, 23, 68 and 14) in the given number (both forward and backward), which have as many digits between them as in the number series. In option 'D', given number: ‘427817431’. There are 2 number pairs (78 and 34) in the given number (both forward and backward) , which have as many digits between them as in the number series.