Question

The number of significant figures in the numbers $672.9$ and $2.520\times {10}^7$ are :

• A. $4,4$
• B. $3,4$
• C. $4,3$
• D. $3,3$

Answer 1

The correct option is A $4,4$

$672.9\to 6,7,2,9\to$ 4 significant digits since all non zero digits are significant.
$2.520\times {10}^7\to 2,5,2,0\to 4$ significant digits, since all the zero on the right side of last non zero digit in the decimal part are significant.