Read the following passage and answer the questions.

Dr. Johnson described sleep as a 'gentle tyrant'. 'Sleep' is a tyrant because nobody can escape its regimen, 'gentle' because there is some flexibility of course, within limits in the distribution of the hours of sleeping and being awake we go to sleep way 15 to 10 hours and sleep for about 8 hours in a 24 hours cycle.

The order limit for keeping sleep at bay for the average individual is 72 hours. An average individual can't keep continuously awake for more than 72 hours. Of course, there have been exceptional individuals like the tyrant Napoleon and Arjuna.

'Sleep' and 'Education' are intimate enemies. Most often they go together, but they always work against each other. Often students lose sleep thinks to fear of failing in the examinations. However, when they sit down to study, sleep overpowers them. Is it possible to develop and impart education about sleep? Has anybody successfully done it? What should be the aims of education vis-a-vis sleep? What are the best agencies for imparting education about sleep and what should be the curriculum for sleep education? There is an urgent need for research in this area.

The longest duration an individual can remain awake is