Max can work for three hours non-stop but then needs to rest for half an hour. His wife can work for two hours but rests
for 15 min after that, while his son can work for 1 hour before resting for half an hour. If a work takes 50 man-hours to get completed,
then approximately how long will it take for the three to complete the same? Assume all of them all equally skilled in their work.
(a) 15 (b) 17 (c) 20 (d) 24