Questions

It is Blackboard or Chalkboard which is Black when clean, and as you write on it with white chalk it becomes dirty in White color.

India is a land of rivers. Rivers are generally treated as mothers and almost every major river of India has a legend regarding its origin.

The Ganges or Ganga is the longest river of India, if we consider the total distance covered by a river within India. Two major rivers of the Indian subcontinent – Brahmaputra and Indus – are though longer than the Ganges, but the distances these two rivers cover within India are much shorter than that of the Ganges.

The Ganges is the most sacred river to the Hindus. The Ganges originates from Gangotri Glacier (Uttarakhand). The total length that the Ganges covers during its journey is 2,525 kilometers (1569 miles) before it discharges in the Bay of Bengal.

The Godavari, also known as 'Dakshin Ganga' – the South Ganges, is the second longest river of India. It originates from Triambakeshwar, Nasik (Maharashtra), and travels through Chhattisgarh, Telangana and Andhra Pradesh, before discharging into Bay of Bengal.

The given letter equation puzzle means that 

7 W of the W = 7 Wonders of the World.

Alcohol has a freezing point as low as -117oC. So it won't freeze even in very cold countries.

Ang Dorjee

A compass, which is used to assist in navigation, is an instrument that shows magnetic north. You must apply a correction to determine the direction of true north. The ability to steer a boat by a compass is useful if land is out of sight, visibility is reduced, or the boat operator is disoriented.

Mount a boat compass away from iron, magnets, and electrical wiring and equipment.