3 of them.
To figure out how many significant figures there are in a number you must first know the rules. All numbers 1-9 are counted towards the number of significant figures. The only number you need to worry about is 0.-If there are 0's between digits (like 105), they are counted towards sig figs.-If, to the right of a decimal point, the number ends in a 0, or multiple 0's (4.660), they all count towards sig figs.-If, to the left of a decimal point, the number ends in 0 (4500), the 0 (or this case zeros) do not count towards sig figs.-If there is a lone 0 to the left of a decimal point (0.112), the 0 does not count towards sig figs.With the number 3.0800, you know that the 3 and the 8 both count towards significant figures. The 0 in between them counts as well. Then the two 0's at the end count towards sig figs. In all the number 3.0800 has 5 significant figures.
Count all the digits, from the first to the last non-zero digit. Include any zeros in between in the count. For example, 105 and 10500 both have three significant digits. Also include any zero after the last non-zero digit, only if it comes after a decimal point. Thus, 0.001050 has four significant digits, since you need to count the last zero.
105
105 ÷ 40 = 2.625 or twice with a remainder of 25.
There are many different ways you could divide 105 objects or people into groups. You could have one group of 105, or 2 groups of 52 and a half objects for example.