A chemical vat has two pipes. The first pipe can fill the empty vat in 18 minutes, while the full vat can be emptied by the second pipe in 30 minutes. What is the time required to fill one-third of the vat when both pipes are open together?

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?