Mumbai has been ranked the world's second most densely populated city with 31,700 people per sq km, by the World Economic Forum (WEF) citing UN Habitat Data. Bangladesh's capital Dhaka topped the list with 44,500 people per sq km. Rajasthan's Kota has been ranked the world's seventh most densely populated city with 12,100 people per sq km.

Milk = 3/5 x 20 = 12 liters, water = 8 liters

If 10 liters of mixture are removed, amount of milk removed = 6 liters and amount of water removed = 4 liters.

Remaining milk = 12 - 6 = 6 liters

Remaining water = 8 - 4 = 4 liters

10 liters of pure milk are added, therefore total milk = (6 + 10) = 16 liters.

The ratio of milk and water in the new mixture = 16:4 = 4:1

If the process is repeated one more time and 10 liters of the mixture are removed,
then amount of milk removed = 4/5 x 10 = 8 liters.

Amount of water removed = 2 liters.

Remaining milk = (16 - 8) = 8 liters.

Remaining water = (4 -2) = 2 liters.

Now 10 lts milk is added => total milk = 18 lts

The required ratio of milk and water in the final mixture obtained

= (8 + 10):2 = 18:2 = 9:1.

Here distance d = 800 mts

speed s = 63 - 3 = 60 kmph = 60 x 5/18 m/s

time t = 800x1860x5= 48 sec.

The Indian Institute of Technology (IIT) Kharagpur has collaborated with the British Geological Survey (BGS) to turn Varanasi into a smart city. As part of the project, three dimensional geological modelling of the geology under Varanasi will be prepared to help improve the building of new transport and service infrastructure. The project includes application of geo-scientific methods like drilling, geological, geophysical, tectonics, hydrogeological and remote sensing. It would be the first major 3D subsurface urban study and planning of its kind in India, with the ultimate aim of developing methodologies and input of suburban geology for planning and hazard risk assessment. The purpose of the project is to develop the methodologies and approaches of urban geosciences and engineering of Varanasi as a pilot for other Indian cities.

India’s first contactless business credit card has been launched by ICICI bank in association with Jet Airways, India premier international airline, for Small and Mid-sized Enterprises (SMEs) and their employees. The card has been christened as the ‘Jet Airways ICICI Bank Business Advantage Card’, which helps customers to save on their business expenses. The card is powered by the ‘VISA payWave’ contactless technology that enables the cardholder to make payments by simply tapping the card at contactless enabled terminals in more than 48 countries, including India. The card can also be used by dipping or swiping at non-contactless merchants.

The GVK group-run Mumbai airport has become the world’s busiest amongst the single-runway facilities by handling 837 flights a day or one in 65 seconds on an average in fiscal 2017.

Telangana has introduced a logo for identifying vehicles driven by persons with hearing impairment and has become the first state in the country to do so. 

The logo was designed by city-based graphic designer Manikanta Annapragada who was the first person to obtain a driving licence under the ‘hearing impaired’ category in the country.

The logo consists of a hearing impaired mark along with text saying, “Driver is deaf — Please watch out”.

Speed of train relative to man = 67 - 7 = 60 km/hr.
= 60 x 5/18 = 50/3 m/sec.

Time taken to pass the man = 600 x 3/50 = 36 sec.