i found a 64bit fpu which needs 20 nanoseconds to perform addition operation.
Also i know that a computer equipped with an fpu performs faster than a computer
that lack fpu.Now i would like to know how much time does a 32 bit floating point
needs to perform the addition operation,also how much time it takes for a computer which doesnot have a fpu.

 

There is no answer to your question.
You have to specify actual part numbers and clock frequencies in order to determine exact execution times.