Three pipes can fill a cistern in 10, 15 and 20 hours, respectively. The three pipes are opened one after the other in the given order, with a fixed time gap between them. If the cistern is filled in exactly 5 hours and the first pipe is opened at the start of the 5 hours, find the time gap (in minutes) between the opening of successive pipes.

Which Indian independence movement leader was primarily known for his philosophy and practice of non-violent civil disobedience?

Who gave the call for 'Do or Die' during the Quit India Movement in 1942?

Which of the following revolutionary pairs were imprisoned together in Cellular Jail and faced harsh conditions, contributing significantly to the Indian independence movement?