Answer :
The significant figures in P (0.0030m), Q (2.40m), and R (3000m) are 2, 3, and 1, respectively. Therefore, the correct choice is (b).Therefore the correct option is b.
The significant figures in a number represent the digits that carry meaning contributing to its precision. This includes all non-zero digits, any zeros between significant digits, and any trailing zeros in the decimal portion. Let's look at each provided value to determine the number of significant figures.
- P = 0.0030m: The leading zeros are not significant; they merely indicate the placement of the decimal. The number has two significant figures (the '3' and the trailing zero after the decimal point).
- Q = 2.40m: This number has three significant figures. The digit '2' is significant, as is the zero because it comes after a decimal and is between significant figures.
- R = 3000m: Without additional context such as a decimal point or notation, we cannot know if the trailing zeros are significant. Thus, we assume they are not and count only '3' as the significant figure.
Therefore, the significant figures in P, Q, and R are respectively 2, 3, 1, making the answer to the question (b).
