948 or 9.48 x 10^2
There are two sets of rules for significant figures
• One set for addition and subtraction
• Another set for multiplication and division
You used the set for multiplication and division.
This problem involves addition and subtraction, and the rule is
The number of places after the decimal point in the answer must be <em>no greater than the number of decimal places in every term</em> in the sum.
Thus, we have
78.9
+890.43
-21.
= 948.33
The "21" term has the fewest digits after the decimal point (none), so the answer must have no digits after the decimal point.
To the correct answer is 948 = 9.48 x 10^2. It has three significant figures.
Given the equation N=O/P, solve for P by multiplying the left and right by P/N:
N * P/N = O/P * P/N
P = O/N
It is either mass or volume
Ductility - a materials ability to stretch, ie if you pull it apart does it stretch to a wire.
density - ratio of volume to mass
conductivity - materials ability to conduct a current.
hopefully with these definitions you can figure out the answer.
