The local mean time at a place located in longitude 90°

The local mean time at a place located in longitude 90° 40' E when the standard time is 6 hours and 30 minutes and the standard meridian is 82° 30' E is

1. 5 hours, 2 minutes and 40 seconds
2. 5 hours, 57 minutes and 20 seconds
3. 6 hours, and 30 minutes
4. 7 hours, 02 minutes and 40 seconds

Difference between standard meridian and longitude of place = 90° 40' E – 82° 30'. = 8° 10'.
1° means 4 minutes

∴ 8° 10' means		49		°
		6

∴ Time =	49°	× 4 = 32 min 40 seconds
	6

∴ Total time = 6 hours + 30 min + 32 min 40 sec = 7h 2 m 40s.