Question

Which one of the following binary number is the prime number?
A. 111101
B. 111010
C. 111111
D. 100011

Answer 1

Correct Answer - A
`111101=1xx2^(5)+1xx2^(4)+1xx2^(3)+1xx2^(2)+1xx2^(0)`
`=32+16+8+4+1=61` ltbr. Which is a prime number.
(b) `111010=1xx2^(5)+1xx2^(4)+1xx2^(3)+1xx2^(1)`
`=32+16+8+2=58`
Which is not a prime number.
(c ) `111111=1xx2^(5)+1xx2^(4)+1xx2^(3)+1xx2^(2)+1xx2^(0)`
`=32+16+8+4+2+1=63`
Which is not a prime number.
(d) `100011=1xx2^(5)+1xx2^(1)+1xx2^(0)`
`=32+2+1=35`
Which is not a prime number
Thus, option (a) is correct.