The uncertain digit in the measurement of a length reported as $41.68 \,cm$ is ...........

The length and breadth of a metal sheet are $3.124\,m$ and $3.002\,m$. The area of the sheet is: (in $,m^2$)

An object of mass $m = 3.513 \ kg$ moves along the $x$-axis with a velocity of $5.00 \ ms^{-1}$. The magnitude of its momentum can be recorded as $...... \ kg \ ms^{-1}$.

The number of significant figures in $3.78 \times 10^{22} \ kg$ is

The mass of a box measured by a grocer's balance is $2.30 \ kg$. Two gold pieces of masses $20.15 \ g$ and $20.17 \ g$ are added to the box. What is
$(a)$ the total mass of the box,
$(b)$ the difference in the masses of the pieces to correct significant figures?

Value of round off of numbers $2.745$ and $2.735$ up to $3$ significant digits will be