In each of the following questions four of the given five are alike in a certain way and form a group .Which is the one that does not belong to that group in the following questions ?

Options

A. 110011
B. 111111
C. 111001
D. 101111

Answer

D

Explanation

Convert these numbers from binary system into the decimal system i.e.

`rArr1xx2^(5)+1xx2^(4)+0xx2^(3)+0xx2^(2)+1xx2^(1)+1xx2^(0)`
`=32+16+0+0+2+1=51`
(b) 111111
(c ) `rArr1xx2^(5)+1xx2^(4)+1xx2^(3)+1xx2^(2)+1xx2^(1)+1xx2^(0)`
`=32+16+8+4+2+1=63`
(c ) 111001
`1xx2^(5)+1xx2^(4)+1xx2^(3)+0xx2^(2)+0xx2^(1)+1xx2^(0)`
`=32+16+8+0+0+1=57`
(d) 101111
`rArr1xx2^(5)+0xx2^(4)+1xx2^(3)+1xx2^(2)+1xx2^(1)+1xx2^(0)`
`=32+0+8+4+2+1=47`
(e ) 100111
`rArr32+0+0+4+2+1=39`
Except 47 , all other numners are composite numbers 47 is a prime number.