The Solution:
To determine the number of significant figures in a number use the following three (3) rules:
i. Non-zero digits are always significant.
ii. Any zeros between two significant digits are significant.
iii. A final zero or trailing zeros in the decimal portion ONLY are significant.
[tex]85.3\text{ is 3 significant figures}[/tex][tex]50.05\text{ is 4 significant figures}[/tex][tex]1210\text{ is 4 significant figures}[/tex][tex]36.05\text{ }is\text{ 4 significant figures}[/tex]
Thus, the numbers: 50.05, 1210 and 36.05 have 4 significant figures.
Therefore, the correct answers are: option B, option C and option D
