Each side of a cube is measured to be $7.203 \; m$. What are the total surface area and the volume of the cube to appropriate significant figures?

$A$ student measuring the diameter of a pencil of circular cross-section with the help of a vernier scale records the following four readings: $5.50\, mm, 5.55\, mm, 5.45\, mm, 5.65\, mm$. The average of these four readings is $5.5375\, mm$ and the standard deviation of the data is $0.07395\, mm$. The average diameter of the pencil should therefore be recorded as:

The number of significant figures in all the given numbers $25.12, 2009, 4.156$ and $1.217 \times 10^{-4}$ is

Each side of a metallic cube of mass $5.580 \text{ kg}$ is measured to be $9.0 \text{ cm}$. Keeping the significant figures in view,the density of the material of the cube can be best expressed as $X \times 10^3 \text{ kg m}^{-3}$,where the value of $X$ is:

The side length of a cube is $1.2 \times 10^{-2} \ m$. Calculate its volume.

Assertion $(A)$: The number $0.00764$ has three significant figures.
Reason $(R)$: If the number is less than $1$,the zeros on the right of the decimal point but to the left of the first non-zero digit are not significant.