Questions

The given letter equation puzzle means that 

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

Harappa was the earliest city discovered in India.

Ang Dorjee

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

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.

Moscow 37o and Los Angeles 118oW show a longitude difference of 155o across the Atlantic and of 205o across the Pacific.

Let the required number of minutes = M
Total minutes between 3o'clock and 6o' clock = 180 minutes
M + 50 + 4M = 180
5M + 50 = 180
5M = 130
M = 26 minutes.