The correct option is (b) M.2^E(1/2<M<1)
The explanation is: The binary floating point representation commonly used in practice, consists of a mantissa M, which is the fractional part of the number and falls in the range 1/2<M<1, multiplied by the exponential factor 2^E, where the exponent E is either a negative or positive integer. Hence a number X is represented as X= M.2^E(1/2<M<1).