The number of significant figures in $6.25 \times 10^5$ is

The decimal equivalent of $\frac{1}{20}$ up to three significant figures is

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

The radius of the Earth is $6371 \ km$ and the radius of its orbit around the Sun is $149 \times 10^6 \ km$. The order of magnitude of the diameter of the orbit is greater than that of the Earth by

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 $\,s$)

If $97.52$ is divided by $2.54$,the correct result in terms of significant figures is