Answer: The answer is [tex]8.4\times 10^8[/tex]
Explanation:
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
The rule apply for the multiplication and division is :
The least number of significant figures in any number of the problem determines the number of significant figures in the answer.
Thus for product of [tex](2.1\times 10^3)\times (4\times 10^5)[/tex]
In this problem, 2.1has 2 significant figures and 4 is an exact number with infinite significant digits thus product will have the least number of significant figures which is 2. So, the answer will be in 2 significant figures.
Therefore, the answer is [tex]8.4\times 10^8[/tex]
