The floating point numbers have the following form:
s = sign
e = exponent
m = mantissa
The bit layout of a
Java float is:
s eeeeeeee mmmmmmmmmmmmmmmmmmmmmmm(23 m's)
The mantissa of of a float which occupies only 23 bits, has 24 bits of presion. The most significant mantissa bit is predictable and not included. Now on to your question. The special values have these forms:
+ infinity: 0 11111111 00000000000000000000000
- infinity: 1 11111111 00000000000000000000000
NaN 0 11111111 10000000000000000000000
(please note that NaN has a one bit at the most significant possition)
Now that you have the bit representation you will be able to easily understand his question.