The radius of a disc is $1.2 \; cm$. Its area according to the concept of significant figures will be given by

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?

Match the number of significant figures in the given column:

Column-$I$	Column-$II$
$(a)$ $0.007\ m^2$	$(p)$ $2$
$(b)$ $2.64 \times 10^{24}\ kg$	$(q)$ $1$
$(c)$ $0.0021\ g\ cm^{-3}$	$(r)$ $4$
$(d)$ $0.0006032\ J$	$(s)$ $3$

If $N_A, N_B$,and $N_C$ are the number of significant figures in $A=0.001204 \ m$,$B=43120000 \ m$,and $C=1.200 \ m$ respectively,then:

If the length of a rectangular plate is $1.5\, cm$ and the width is $1.203\, cm$, then its area is ............ $cm^2$.

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