Question

Given the numbers: 161 cm: 0.161 cm: 0.0161 cm. The number of the significant figure for three numbers is:
(A) 3, 4, 5
(B) 3, 3, 3
(C) 3, 3, 4
(D) 3, 4, 4

Answer 1

Hint: Significant figures mean important figures or we can say that the digits that we use to express the required degree of accuracy, starting from the first non-zero digit. Or we can say significant figures are any non-zero digits or trapped zeros. Recollect the rules of significant figures to get the answer.

Complete step by step solution:
Let’s recollect the meaning of significant figures and some of its rules.
Significant means important or meaningful or needs to be considered. It should be noted that significant numbers are those that are written in positional notation and these digits carry meaningful contributions to its measurement resolution.
Significant figures include all numbers except leading zero.
Significant figures exclude all leading zeros. For example, we should note that in "013". It has two significant figures: 1 and 3. Leading zeros are never significant: 0.02, 001.887, and 0.000515.
All non-zero digits are significant. All-natural numbers are significant i.e. 1, 2, 3, 4, 5, 6, 7, 8, 9 and zeros between non-zero digits are significant: 102, 2005, 50009.
We know that zeros to the right of the significant figures are significant, if and only if, they are justified by the precision of their derivation. For example, 13.4300 may have six significant figures: 1, 3, 4, 3, 0 and 0.
Now, coming back to our question we will now answer our question. From the above rules, we can say that all the numbers have three significant figures.
At first, 161 had three significant figures.
0.161 Also have three significant figures and so 0.0161 have also three significant figures.

So, from this, we can say that option C is correct.

Note: Let us know about accuracy and precision. Accuracy refers to the closeness of a given measurement to its true value. Whereas, precision refers to the stability of that measurement when repeated many times. Remember, in 0.01, zero before decimal is non-significant and thus, its significant figures are only two.