The length,breadth,and thickness of a block are given by $l = 12 \, cm$,$b = 6 \, cm$,and $t = 2.45 \, cm$. The volume of the block according to the rules of significant figures should be:

"Changing the units of measurement does not change the number of significant figures." Explain with an example.

For the four sets of three measured physical quantities as given below,which of the following options is correct?
$(i)$ $A_{1}=24.36, B_{1}=0.0724, C_{1}=256.2$
$(ii)$ $A_{2}=24.44, B_{2}=16.082, C_{2}=240.2$
$(iii)$ $A_{3}=25.2, B_{3}=19.2812, C_{3}=236.183$
$(iv)$ $A_{4}=25, B_{4}=236.191, C_{4}=19.5$

The number of significant figures in the measured value $4.700 \,m$ is the same as that in the value ....... $m$

Time periods of oscillation of the same simple pendulum measured using four different measuring clocks were recorded as $4.62 \,s, 4.632 \,s, 4.6 \,s$ and $4.64 \,s$. The arithmetic mean of these readings in correct significant figures is: (in $\,s$)

What is the number of significant figures in the result of $(3.20 + 4.80) \times 10^5$?