What does double precision mean?

• A. It uses twice as many bits for the mantissa as single precision.
• B. Floating-point format with more bits for significand and exponent than single precision.
• C. It uses fewer bits than single precision.
• D. It is used only for integer values.

Answer: (B)

Double precision means using a floating-point format that stores numbers with more bits than single precision, giving a larger exponent range and a larger significand (mantissa). That extra bit budget lets you represent much bigger and much more precise numbers. It isn’t just about doubling the mantissa; both the significand and the exponent get more bits, which is why the correct description says “more bits for significand and exponent than single precision.” The other ideas don’t fit: using fewer bits would reduce range and precision, and doubles are not limited to integers—floating-point numbers handle non-integers as well.