Answer:
Explanation:
Exact numbers are those numbers which are known with 100% certainty or accuracy . Numbers having decimal are generally not exact because they are a part of long drawn decimal number after rounding off to certain places after decimal.
On the basis of this definition we can say as follows
speed of light is 2.99792 ×108 . Here the number quoted is not an exact number because it is a rounded off figure of speed of light to five digits after decimal .
Similarly density of mercury too is rounded off to two digits after decimal
so it is also not a exact number.
There are 3600 s in 1 h . Here 3600 s is an exact number because one hour has been defined as 3600 s . It is not measured by any instrument.
In 2003, the United States had 50 states. Here 50 is an exact number .
