3. The population of a city in 2000 is 50, 000. The average per decade of the previous records of population is 5000 and average percentage per decade is 20%. The population of the city based on geometrical increase method, in the year 2020 will be
5. The depth of the water table at a place is 45 m below the general ground level. To lift water from a deep tube well in such a locality, the type of pump to be installed is